Wide-band Lambda AFR reverse SuperTrapp tuning and FAQ confirmation

As the SuperTrapp FAQ recommends, you should alter the number of exhaust diffusers, ride and determine if performance is more or less to your liking. Well, I now have a tool to take the guesswork out of the equation, confirm riding impressions, but arrive at the same desired result. This time, there's no arbitrary seat-of-the-pants impressions that could go either way. :confused: A wide-band Lambda sensor will give me 100% absolute real-time air to fuel ratio numbers to tell me how well I've tuned my Supertrapp and thus, my carburetors.

The AEM wide-band Lambda AFR digital readout and O2 sensor (30-4110*) was installed last year on my 900 Ninja (ZX-9R). I recorded many of the results over a variety of riding conditions. Last years readings however were on a different motor, running different engine coolant. Since it was cheaper to swap to a younger motor than to even replace the oil seals in my 128,000 mile motor, I now have a much lower mileage motor, but also running waterless engine coolant.

The combination of light oil leakage fouled my original AEM O2 sensor and eventually burned out the digital Lambda readout. One warranty replacement later, it's all working again and I have new numbers, different from before even though my carburetor jetting is mostly unchanged from before. I've confirmed my mid-range jetting is too lean, 15.2:1 lean at 55 MPH. Conventional SuperTrapp FAQ wisdom says to remove one or two diffuser plates to boost performance, get the AFR back below 14.7:1. Only this time, when I do, the AFR readout will tell me how much closer I am to ideal. My plan is to tune either only my SuperTrapp and/or my mid-range jet needle height to arrive at more ideal AFR numbers that I was seeing from the bike last year.

For those wondering or a bit puzzled about how an AFR readout got on a carburetted motorcycle, it's aftermarket.

https://uniim1.shutterfly.com/ng/ser...nhance/O2a.jpg
https://uniim1.shutterfly.com/ng/ser...a-ZX-9RsE1.jpg

* 30-4110 is the full kit. The cheaper 30-4110NS version stands for No Sensor, as in no O2 sensor.

When it contributes 5% to the gap of combined diffusers with a closed end-cap, it's enough to drop AFR on my 899cc sportbike as follows:

I don't know how to calculate surface area, so I'm just going with a numeric factor of the combined diffuser gap. AFR is about 0.2 lower up to 3K RPM, 0.3 lower at 3.8K/55 MPH and 0.5 lower at 4.7K/72 MPH.

Once it's safe for an interstate tank run, I'll know more about how this translates. I have some numbers recorded from last month for a baseline to compare to. And I was already satisfied with mid-range oomph, but it feels like there's a little bit more. If that's just in my head, it did seem like I made a mental bookmark of how the bike pulled, lighted the front wheel. I don't remember it doing that prior to tonight.

Circumstantial riding last week. Got a wild hair after fueling in a couple gallons. Told myself that it was okay to put some miles on the bike up into the nearby mountains, just go easy, lean the bike, but take it smooth and slow. Noticed a car about a mile up ahead at the base of the mountain, waiting. Thought I was going to get lucky and they'd wait for me to come by them for whatever they were waiting for and I'd hit the jackpot on some clear sailing. Turned out to be two cars, a Suburu WRX (turbo?) and the lead vehicle looked to be an Audi of some sort (A4/A6), they pulled out in front of me conveniently. They were definitely going to hotrod up the mountain as a pair and since I was the last vehicle for a while that had gone by, they had a lot of room up ahead to play.

Here we go. :no :evil: (my own worst enemy)

Yes, I wanted to see what they had. :mad: I let them race into the first curve, while I held back. If they were really fast, I'd have my own room to play, but if they were slow, it was going to suck. The Audi braked into the corner, so he was pushing and actually appeared to come out of the corner pretty fast. I'm sure in their cars they probably felt like they were pulling some Gs and they thought they were going to dust the green sportbike. No way to tell until I dropped a knee down into the corner myself to find out.

I made up several hundreds of yards on them in the first two corners and was already on the tail of the trailing WRX going into the third corner. He had to of seen me flying up behind him, b/c he gunned it going into a RH sweeper before a parabolic 25 MPH LH corner. He must have been beyond his comfort level though, b/c he was well over the centerline, sliding and throwing back a cloud of dust and debris at me, so I slowed and veered to the outside to avoid. They continued on and were making good time in the next faster 30 MPH corners, but up ahead was another series of 25s. I was only catching them a little in the 30 MPH corners, but I was all over them like a cheap suit when we got to the 25s. They were belching out a lot of black smoke and you could hear their engines whining and thumping along. There was every indication they were trying to run. Try as they did, it just wasn't working out how they probably envisioned after jumping in front of me.

I was just carrying my energy through the corners in a fluid motion, lugging the bike around in 6th gear. The WRX must have gone in too hot or missed a gear on the second 25 MPH LH'er, b/c he lost a lot of momentum. I had to panic brake to avoid running into the back of him. Couldn't understand why they were going in so fast and parking it in the corners.

Up ahead was slower traffic so I slowed to 50 MPH to let them as a pack move ahead, giving some spacing so I could have some fun in between catching back up to them. When I rolled on the throttle WFO I was probably at about 6,500' AMSL, the AFR went into the low 10s and the bike struggled to accelerate. :-k Rolling off a little brought the AFR up a little again and the bike lunged forward. Sounds like my mains are still too rich on average for the new engine and where I typically ride. I did my corners at my pace and caught back up to them about 1/4 mile ahead. The slower vehicles all moved out of the way and it was just us three and hopefully clear sailing. Again I let them take a sizeable lead, before turning up the pace going into the next sweeping corner. I began to get the impression they weren't good drivers, just kids who dumped a reasonable amount of money into their lowered cars, but sorely lacking in their driving skills & confidence. I could catch them at-will, which was turning out to be somewhat fun, somewhat aggravating. They'd accelerate to about 90 MPH on the straights and I'd stay down at about 55 to let them go, then as they'd hit the corners up ahead, I'd accelerate, take the corner without slowing, carry more speed into the next, reel them in at somewhat of an alarming rate and repeat the yo-yo.

Having had my fun, point made, I turned around midway up. I think that was another fateful decision, b/c about two miles behind us was a state trooper coming up. He wasn't going terribly fast and I doubt he saw any of our dumb foolery, but I played it cool going back down and kept checking behind me to see if maybe he knew more than I thought and had turned to come after me. It wouldn't be the first time someone had called us in, but fortunately I never saw him again.

Uneventful ride home and way way more than I should have risked given the S.A.H. orders. But it felt good to scrub the rust off and find some rhythm. It was also a little shocking about how it played out tonight, actually pacing cars that were definitely oversteering a bit in the slow corners. I'd read so many encounters where the results were the opposite, due to the greater contact patch of four tires on the sports cars. So the kids tonight must have really sucked! They made my night though!

Coming downhill at about 60 MPH the readout was showing about 16.2:1 at steady coasting throttle, dropping from there if I gave it any throttle. Altitude didn't seem to make much difference. There was a headwind when I made the highway on the way back. Interestingly, at the same speeds on the return of ~75 MPH the AFR was about 0.4 leaner than with a tailwind on my way out, so the airbox pressures do translate to more air than fuel under higher airbox pressure conditions. In fact, they appeared to move directly proportional to wind gusts. So to carry that thought forward, my conclusion would be that AFR readings performed during dyno runs in static shop air are inaccurate to real world conditions.

I've plotted the numbers into a spreadsheet, much like on a dyno chart, with riding impressions and mileage results...if that ever becomes a possibility.

This has everything to do with a motor refresh I did over the winter. The new engine doesn't like the old engine's carburetor settings. So right after, I dropped the main jets one step. But was still getting a too-rich condition only at WOT.

https://uniim1.shutterfly.com/ng/ser...nce/AFR101.jpg
https://uniim1.shutterfly.com/ng/ser...nce/AFR100.jpg

So yesterday I dropped the main jets another step, but left the SuperTrapp diffusers the way they were. I want to see the results first, before maybe adding the one diffuser I removed back.

That took care of the WOT/WFO flat spots, but was still able to occasionally get a 10 to show at WOT, so I might put the one SuperTrapp diffuser back. Noticeable pickup in midrange too by going with the leaner main jets. The lowest AFR witnessed was a 10.8:1 and it didn't feel like it prevented acceleration, even at higher altitudes. Only saw it for a split second, before the readings went more into the mid-11s. Mind you, this is on a RAM air bike, not one that relies only on atmospheric pressure.

AFR at Idle is still about the same as before, but under acceleration I'm mostly seeing ~12.5:1. At steady throttle from 1.5K - 3.2K it gets continuously leaner as we all would suspect, then steadily drops from 3.2K to 5K RPMs anywhere from high 14s into the lower 13s. Above that it doesn't change much unless I'm accelerating hard, then no matter what the RPMs are, I'm seeing 11s & 12s. Acceleration is quite good even when it shows 11s, surprisingly. At higher altitudes doing some 6th gear roll on/off/on does kind of throw out some crazy numbers. Some of that probably has to do with exhaust gas lag in getting to the O2 sensor to be measured.

In downhill riding scenarios at steady throttle it's common to see high 15s, low 16s. Off-throttle, low engine loading really doesn't mean anything other than that the engine isn't adding much fuel to basically spin the motor and to push what little drag there is being produced above 50 MPH. My bike seems to prefer anything from 11.0:1 - 14.7:1 on level ground, at speed.

Throttle response and acceleration throughout the RPM range feels really good and meaty now. I can certainly live with how she's performing:
https://media.tenor.com/images/d02ed...d0ed/tenor.gif
Glad I have this device. I would not have thought the mains to be the current issue without it, but they were exactly the issue.

Now to see how the bike performs at lower altitudes and what kind of MPG numbers the newer motor is truly capable of, without the handicap of jets that were about ~5% too rich for riding conditions.

After several rides to lower and higher altitudes, the best compromise (carbs are a compromise), are their current settings with the diffuser back in place. I need it in there for the higher summits and it doesn't make fueling so lean it's an issue at lower altitudes. If I need to ride at one or the other for extended periods, I can add or remove onel diffuser, but fueling is really good. I'm not at the maximum nor the minimum diffusers, so for me, there is a sweet spot.

But it gets better, because I purchased a second AEM UEGO gauge and wired up my other 2000 Ninja ZX-9R with a Muzzy pipe. With virtually the same jetting, the SuperTrapp bike is head and shoulders above the Muzzy bike in power and performance. I'm still looking to see if the Muzzy exhaust bike can do better at WOT operation with richer or leaner jetting than what's in it now. My sense is that one step leaner is the right way to go, but the UEGO readings off both bikes, say I should try to match the AFR numbers from the SuperTrapp as best as I can to the Muzzy. I know it can do better. I just got its mid-range a ton better, which is resulting in a parallel, but richer fuel graph from 1K - 8K RPM than the SuperTrapp bike's fueling. I definitely need to clean up the mains. At 3/4 - WOT, the Muzzy bike is definitely richer and too rich, making it obvious that 3/4 throttle works better for it than WFO throttle at the moment. But ironically when compared to the SuperTrapp's graph, it's leaner near redline and fluctuating more in the higher RPMs.

The Muzzy bike is a work in progress, so this isn't conclusive for me yet. I'd like to try out different main jets to maximize the WOT performance, per Factory Pro's recommendation, which is to set the mains first and work your way down. Then I can fine-tune the mid-range and clean up the pilot circuit with the help of the EUGO readings.

Comparing the two bikes:
Off the line, SuperTrapp wins. Mid-range, SuperTrapp wins. Top-end, SuperTrapp wins. Rapid throttle response, SuperTrapp wins. Fuel efficiency, SuperTrapp wins. Exhaust weight, Muzzy wins.

Haven't actually quarter miled my two bikes against one another, but I did run the SuperTrapp against another owner's 2000 ZX-9R. His is a lower mileage bike that I helped him rejet this Spring, running the stock exhaust, with a -1 countershaft sprocket for quicker acceleration. He confirmed the changes we made woke his bike up. Then we did about 10 first gear roll-on drag races through 3rd gear mostly him egging me on to show me how quick his bike was. The two bikes were evenly matched in 1st geary, but my SuperTrapp bike was basically walking away from his bike or holding it's own if his bike got the jump on mine. The longer the drag, the further my bike pulled his, even with his acceleration friendly gearing. While I was, I also wasn't surprised at how well my SuperTrapp bike did. This bike scares me enough to know it has a dangerous side that needs to be respected.

Back to the Muzzy bike though, I checked the compression too thinking that must be contributing to it's lack of oomph, but its valve clearances are within specs and compression numbers looked good. So racing the two bikes wouldn't be fair to the Muzzy bike at the moment. It's just not ready and would get its clock cleaned.

I'll know more in a week or two as I experiment more with the Muzzy's jetting. Since its exhaust flow is not adjustable like the SuperTrapp's, jetting is the only thing that I can use to adjust mixture readings. One way or the other, with the AEM UEGO gauge to help guide me, the Muzzy bike should improve to some level where I don't think I can improve it anymore. Then I can make a final determination on how it compares to the SuperTrapp bike. But I'm already eyeing my third 4" aluminum racing series muffler in place of the Muzzy CF muffler. I'm just not confident the Muzzy exhaust does as much for performance as the adjustable SuperTrapp. And performance is a motivator to make changes.

p.s. once the Muzzy bike is tuned ideally, I have my baby, my 2002 ZX-9R (SuperTrapp) that is ready to accept the UEGO gauge too. It's much closer in performance to my 2000 ZX-9R, but I'll be curious to see if it too can benefit some after I draw out it's RPM fuel mapping and compare it to the other SuperTrapp bike. Stay tuned. There's more to learn.

The Muzzy bike is still a work in progress. I checked the valve clearances and replaced the Factory Pro +4 ignition advance with a stock timing rotor. From a previous ride, I started to see a glimmer of hope, but the jetting was too lean though the midrange and too rich on top. So I adjusted the fueling some more, reducing the mains one step and bumping the jet needles up a notch to what Factory Pro recommends as a starting point.

There's no way to sugarcoat it, the Muzzy pipe sounds sterile and stupid, like slapping your hands together in water when opening it up from 1/2 to WOT. Power is awful other than at WOT from 7K RPM up. The bike is just falling on its face by comparison, if I try to ride it like my other SuperTrapp ZX-9Rs. There is power and acceleration there, but it feels like its 15 HP down on the SuperTrapp bikes. For instance, rolling from a stop. With the SuperTrapp bikes, you almost don't need to go above idle while slipping the clutch. It's effortless. With the Muzzy bike, you have to rev it a little and slip the clutch for what seems like an eternity, by comparison. With the SuperTrapp bikes power is like a Tesla's powerful electric motor, it's instantaneous, everywhere and always on tap. With the Muzzy exhaust, if you want the same kind of power, you have to downshift a couple gears and by then, if it was an emergency, it's too late.

But I'm still working on it and I'm getting closer now that the main jets are fairly close and timing isn't interfering. I know what I have to do next inside the carburetors, since I cannot tune using an adjustable exhaust, like with the SuperTrapp's easy to swap diffusers.

FWIW, the AFR is still too rich, but primarily in the low-end and midrange. I think I can take some of that out, split the difference at the jet needle, it will hopefully restore some of the power that's not there like it could be.

I'm serious, I feel like a sitting duck without the SuperTrapp kind of power I'm accustomed to. But I'm going to suffer through it until I think it's as close to ideal as possible, before ordering my aluminum racing series SuperTrapp slip-on. I just want to see for myself what other people experience. And so far, I can see why there are so many owners who are talked into putting on some other aftermarket muffler and soon after sell their bikes. I'm about to that point, except for the fact I know there's a soul in there waiting to be unleashed.

Quite the classic story behind today's 213 miles to reserve. A personal record for this Muzzy equipped bike, its first time over 180.

On Friday I needed fuel in the bike's tank since it was empty and ended up stealing the SuperTrapp 9R's tank out of convenience. It was full and only had 10 miles on it. Rode around Saturday doing a whole lot of WOT and high RPM tests to accumulate AFR data off the UEGO. Figured I'd go for a stroll again with it, not remembering that if I did need fuel I'd need to bring the key to unlock the tank cap. :rolleyes: At this stage however, I was completely unaware, only focused on testing out the new jetting.

I took off for some local hills, a 60 mile loop and I think the odometer showed I'd put about 145 on the day before. Actually was just cruising with it thus far today (Saturday), since I've not ridden this bike in anger, not even once. It hasn't been up to the task, which explains that. At the turnaround on the other side of the mountains, I saw another HD or something coming over the hill towards me, still about 1/4 mile away, so I turned around and kept up my cruising pace through the lower slow MPH zone only to find the HD wasn't a HD, it was a sportbike and he was hauling. So I dropped a knee into the first corner then the second and asked the Muzzy bike for the beans. Not great, but I was accelerating. The other rider was a little further back when I exited the parabolic corner, and I moved over on a short straight to let the guy have the right of way if he so chose. I was content in cruising with my unknown quantity Muzzy. Next thing I knew, he brushed past me, deliberately within a couple feet doing 50 over what I was.
https://www.youtube.com/watch?v=fvEatgBjZ6c
https://imgd.aeplcdn.com/1200x900/bw...andard-792.jpg
Hey, I know that guy. He's on his Kawasaki H2 and he's really moving, probably more so to impress or intimidate the guy on the 20 y.o. sports-tourer. He had carried too much momentum into the turn ahead and had to slam on his brakes, so...oh yeah, let's see if I can keep up with a 200+ HP H2. lol Sure enough, I picked up momentum and reeled him in, making up about 60 yards of the 100+ yards he had on me when he zipped past, as we entered the lower set of corners. In each successive turn, I took another 10 yards out of his H2, then he'd gun it on the straight and pull away, leaving a black rubber line on the road from his rear tire. But not pulling away as much as I would have imagined for a H2 belching out black smoke as he hammered the throttle. He definitely couldn't corner well with the bike. By this time, I was down into 4th gear to get the bike to pull and carry my lines I'd need to catch up to him. Still figured I'd get dusted. I mean, he's an ex-dirt flat track racer with the advantage of a near new state of the art fuel injected supercharged bike at altitude (6,000' AMSL). He knows how to ride fast. He should blow the doors off my sluggish, test-n-tune Muzzy 9R.

The H2 had again taken back the full 100 yards back on me into the next turns after the straight, which had some 180s and elbows. With the help of my upgraded Triumph Nissins (on my Kawasaki I made back about 70 yards on the second of two turns, made up an additional 10 or so in the 180 and the next turn, before he'd launch again onto a longer straight ahead. But this time, in a better gear, I was able to minimize the losses there, somewhat because he choked setting up for the S-turn ahead, slamming his brakes whereas I could carry my momentum through the S and into the next 180 uphill corner. Now I was within 15 yards of him and I came out of those turns within about 10. He launched his H2 for all it was worth, taking back some, then losing it back in a fast LH sweeper that lead into another LH 180 and RH elbow. Going into the 180, with the help of my Nissins, I was again about 10 yards from him and by the time we left the RH'er, I had closed to within feet of his rear wheel. Damn it, though! If I had been on the SuperTrapp ZX-9R, I could have truly messed with his head and gone for a pass much earlier and probably repeatedly. That bike just leaps out of corners, power is like turning a faucet handle. I wouldn't have been successful, of course, but that would have been hilariously funny to do, just so he'd know he'd been owned by a ZX-9R.

And it gets better and worse! Going up the next straight we were both coming in just sub triple digits (KPH ;)), nearing an area where the local sheriff likes to hang out. It was hot out and I was going to toss caution to the wind, simply because what are the chances the sheriff had just showed up and was parked and roasting, just to catch speeders? No way, he's probably back at the station dunking donuts in an air conditioned room.

I again was carrying my momentum after the straight to reel him in and was about to drop the puck on the floor in a blind RH corner when the vehicle going in the other direction was the sheriff! :eek: The H2 rider and I were easily 30 over as we both scrubbed speed off as the sheriff passed by. We were busted, no ands ifs or buts. I thought about pulling off and accepting my fate, but that's never worked out in the past. I'd seen the sheriff's tail lights as he went around the bend behind us. You know that feeling where you just hope he didn't have his radar on or something.

The H2 and I proceeded to ride onward around additional corners, both acting like we were angels, not a couple of hooligans tearing up deserted backroads. I didn't look back over my shoulder, didn't want to. But in my mirrors I couldn't see either the sheriff or him lighting us up. So about 3/4 of a mile ahead, which felt like eternity to get to, I split off into a residential area, while the H2 rider stuck to the main highway. His route only gave him two options. One, onto a road that would double back in the direction we'd come or at the fork up ahead he could continue into a town where there was almost certain to be a deputy. I figured if the sheriff was still turning around or had radioed up ahead to his deputies, he'd only be able to tag one of us this way...and probably not me.

By this time my odometer was at about 175 miles, but I was up high and could coast through the rural residential area to a fire escape road I knew about, if only I could make it there without being detected. The fire road let out down below onto another highway that if I took the short route home, would possibly take me past the sheriff again, if he were lucky enough to spot me out there, so I considered my fuel and felt it would be close, but I was going to take the long way home and go the other way. I was headed directly opposite to my way home and was planning on looping around several other mountain ranges that would probably add another 60 miles to my trip. Mind you, I had no idea what to expect from the Muzzy bike's range. IIRC, it had never topped 180 miles (to reserve) before I'd made changes to the jetting.

But I made it. So no performance award. No stranding. Still feel a little lucky in the circumstances. But the bike came through when I needed it to live up to its potential.

https://uniim1.shutterfly.com/ng/ser...rapp_ZX-9R.jpg

Lately, I’ve been focusing more attention on my SuperTrapp (ST) sE1, because the Muzzy is getting closer to something resembling acceptable throttle response and power. I’m experimenting with new fuel jetting to match to the flow characteristics on my ST and Muzzy exhausts. The reason for that is that I’ve already established what I like. I know the ST worked beautifully on my first two Ninja ZX-9Rs. The number of diffusers isn’t at the maximum nor at the minimum. The ST FAQ helped me arrive at what worked best, great torque and top end, while civilized for around town riding. Not an all-out track-only setup, like my Muzzy will probably take. Thus far the Muzzy exhaust has been a major expectations letdown.

Focusing on my ZX-9R sE1, I tried some shortcuts by adjusting only the jet needle height, similar to what worked on the Muzzy bike, but the results this time were steps back. Factory Pro, which makes jet kits, says in their how-tos to always start with the main jet; set the best main jet first. They are right There is no shortcut to any of the lower fuel circuits until the best main jet is established. Back on track, I found the best main jet at the end of the week. Then methodically, I reset each of the lower fuel circuits based on what my Lambda UEGO gauge was telling me. Two more adjustments and a test ride was all it took.

From the ride on Saturday, August 9th, I still bumped into some 10.9s (AFR) while in too tall of a gear for the slow mountain corners I was in, but high and low, she felt much more like her old (motor) self. Range was phenomenal. One complaint about power, there was a hint of throttle lag, but not always. And that was due to a fueling change, something I'll have to keep an eye on. But otherwise, she just Eff'in boogies and the ST sounds badass!

Lots of high 11s getting on the power on summit curves or passing slower traffic. Cruise AFR (75-80 MPH) is in the 12.9 - 12.5 range. Still richer than I would like for steady throttle, but for now, I think I'm okay with all of it. Top to bottom, bottom to top and everything in between just feels awesome or close to it. How awesome? It makes my Muzzy ZX-9R feel like a 600 from idle up to about 8,000 RPMs. Only then does it begin to rival the ST’s power output. That’s the meat of where I ride on the street. I’m not going to ride in corners at 8K RPM just to be in the Muzzy’s powerband! There’s way too much engine power by then for me to control.

Sunday August 10, 2020, was a hot dry Summer day and also a good test to find weaknesses in my tune. We had planned a group ride which included some summit crossings and elevation changes of greater than 5,000.’ The results however, didn’t find any new weaknesses, so I may still be over-fueling, but the throttle envelope is quite unrestricted, matched beautifully to my SuperTrapp’s flow.

Instead of taking point of the group ride initially, I followed. That afforded me a better vantage point to test throttle response and acceleration under varying conditions without affecting other following riders. Settings confirmed midway through the day, I moved to point for some spirited riding and had the riders stack up behind me going back into the mountains. I stuck to the bike’s top two gears to constrain acceleration, so as not to excessively speed, nor present a danger to anyone out on our mostly deserted 3 - 4 mile twisty mountain road. But I did unleash her in a spirited manner.

We had established at the bottom that we were ready to stop for a late lunch picnic at the top of the mountain, which gave us the forum to tell our ride stories from each rider’s perspective. Once settled in for lunch, the last two riders said they lost touch with us shortly after we hit the curves at the bottom and began the climb. Going faster than they normally did, they were aghast that they could only see the third rider, but not me and one other rider after only a few turns.

The third rider was keeping their own pace and said they were able to see me and one other rider briefly going around a bend midway up the mountain, but also lost touch. The fourth rider, the one behind me was on his Suzuki SV-650 sporting a Leo Vince SBK muffler. He has only been somewhat successful by redlining his 999cc KTM 990 Super Duke trying to keep up on a previous ride on this same mountain. He went on to volunteer in a very animated way that he had his bike pinned in 3rd and 4th gears giving it everything he had to unsuccessfully chase down my 9R. He made some jokes too, in jest, of course, but followed up by repeating several times to me his astonishment of the situation he believed would turn out much differently, that my ZX-9R was no joke. Even with a more nimble bike, he said in a disheartened tone, that my 9 just disrespected his Suzuki everywhere. And by the time we finished the main series of twisties a few miles later, the gap between us had stretched to several hundred yards before we both slowed to allow for the other riders to regroup.

Not my Muzzy ZX-9R and not just any plain old ZX-9R. My Ninja ZX-9R, one of two that I own with awesome SuperTrapp mufflers. And now for the record, apparently it is this 2000 model ZX-9R sporting an aluminum racing series SuperTrapp that is in his words, no joke.

Observed a lot of 11.4s climbing and some 17s descending. Exceptionally hot in the latter portion of the day. No pinging and I tried to make her ping. She wouldn't do it, no matter the gear, load, how hot the engine coolant temp was or throttle position. One constant is that no matter what the steady throttle reading is, opening the throttle makes it lower. For fun, on the way home we each did one run at the old airstrip. I took it up to 135, which at WOT showed a ~12.5:1. The trend was heading leaner from the 11s it was showing going through 110 MPH in top gear. Some of that could be skewed by the hot dry air temps and altitude too.

As circumstance would have it, I had to take my backup bike, my other SuperTrapp ZX-9R, for a group riding trip. We met several other riders, most who were on sportbikes too. By day we rode curvy roads. By night we social distanced at the local brewery. Good times. Eventually, as all festive trips go, it was time to head for home. In one last opportunity to ride together, we rode out of our way to take in the windiest road we could find. And because one of our riders brought their Ducati Panigale V4-S, an 1103cc 219 horsepower fire breathing obnoxiously loud sportbike eater, we were required to stop every 70 miles or so for him to take on fuel. In our last stop for fuel, I flipped the cameras on to share the experience.

My backup ZX-9R hasn't undergone the complete UEGO conversion just yet. I'm still assembling information on my other two bikes. But the tune on my 9R isn't far from perfect, just not the same as the other two at the moment. The O2 sensor is already installed though.
https://uniim1.shutterfly.com/ng/ser...e/ZX9R_sF1.jpg

We had six riders in our ride group. The Ducati and KTM riders are trackday regulars, each capable of lapping 20+ seconds/lap faster than I can on my 9Rs, but it's been a while since I've been to the track. Some of that has to do with my fear of accidents at speeds I wouldn't ever see on the street. So my only comparison with them is from technical curvy roads we ride together. The order is ZX-9R, Panigale, Super Duke.

https://uniim1.shutterfly.com/ng/ser...S_ZX9R_sF1.jpg

On went the cameras. My primary concern was safety and not holding up my faster track riding buddies. SuperTrapp power didn't disappoint. I edited the full video down to just the unobstructed portion and sped it up so it would appear more exciting. At the mid-start, a slower vehicle had just moved over to let us through, so I stretched the legs a little, then slowed on the next straight to regroup.

https://www.youtube.com/watch?v=IBRgdr7-Z4Q

* Pronunciation

Got the old girl fixed. It was my mistake putting the original burned out fuel pump into the bike, thinking a simple filing of the contact points would solve it. Apparently on some of them, when they fail they stay on and end up draining the battery while you're riding, just like what happens when the stator on a motorcycle or alternator on a car fails. Lesson learned. She has a new fuel pump and 250 miles under her now.

She's just shy of 143,000 miles. I know she's old and many would discard such a bike at that age or sell it for something newer, but she's without debate my bike of choice. It almost feels like I'm still getting her customized to my liking, each iteration feels better than the last.

For her maiden voyage we took her out riding into the mountains with two other sport riders. One was on a new KTM 790, the other on a Ducati 1098. She was not only the class of the field, able to gap them or chase them down depending on how we lined up, she was running in her normal 2.5x their range mode. So either they were pushing and burned a lot more fuel or they weren't pushing and they still burned more fuel. I've seen the videos of them riding, so I'm guessing they were pushing.

https://uniim1.shutterfly.com/ng/ser...e/sE1_2020.jpg

I half heartedly joke about how there almost appears to be this dependency where riders after a season or two riding along with the SuperTrapp ZX-9R sE1 or my 2002 sF1, also with a SuperTrapp muffler, shortly thereafter sell their bike for something better. Yeah, ha-ha, try as they will, try as they might, by the end of the ride the sE1 is leading them home. They're often tired, beat, and seemingly a little grumpy sometimes, scratching their heads about the ZX9 they cannot figure out. Or maybe that's simply down to them not feeling it on those days. Whatever, right?

In the past week, I had some work to do which afforded me the opportunity I'd wanted to take the sE1 out to build confidence again that the electrical woes are behind her. The work happened to be at my buddy's house, one who rides with me somewhat regularly, so I took the bike to and from (without incident).

I wrapped up my work and we took a break with his family (social distancing-like, with masks) watching motor racing replay highlights and I mentioned this bizarre thing that happened to me on the Internet that day. The site link took me to this infected Web site with a hook title about the 2021 H2. Blah, blah, blah... I finish my story and he says, you know your buddy with the H2 sold it, right? I reply no, but I was thinking he was pulling my chain, typical for him. All except for the fact that I've never explained to him my hypothesis from above. But he continued on matter-of-factish straight faced yawning. Yeah, he says, about two weeks ago. I spoke to him this week and he said he sold it. The H2 is gone.

No way, I reply, thinking here we go again! He sold it?!

I'm not exaggerating, that guy loved, talked up, and babied that H2! Every time we saw him, that bike was his pride and joy, focus of his world of attention. It's the only one in these parts, king of the hill. No question about it. Always clean, just a gorgeous mean looking beast of a bike. And for the brief mile or two he would ride with us, it was always on straight roads where he'd gun it or power wheelie at speed to show the obscene acceleration it had, before pealing off and doing his own thing while we headed towards the mountains.

He picked the bike up new in 2015, so he was the only owner. The guy who would show off the bike's untouchable power characteristics, even gave me a good reminder of it in case I'd forgotten when he rudely buzzed me that day months back. And now suddenly it's no longer the apple of his eye? That's one freaky coincidence!

I can't know what made him sell his supercharged H2, but it's not my intention to spoil other riders love of riding or attachment to their bikes. If anything, it’s just the opposite. I wish they could take as much enjoyment from riding as I do from the experiences I relish aboard my SuperTrapp ZX-9Rs.

There she is, my SuperTrapp sE1, the old girl with all of her miles and wear-n-tear! Got really lucky threading storm cells today. A bit chilly at times, especially on the ride home, but hand warmers helped out with that. Although this looks sunny and mild, it was just the sun peaking through momentarily before turning cloudy again. It sure felt good on my suit while it lasted.

Got rained on briefly before and after this, but was able to alter my course enough that the bike didn't get too messy from the mucky road spray. Oh man. SuperTrapp muffler systems and the Kawasaki Ninja ZX-9R. What a combination!

https://uniim1.shutterfly.com/ng/ser...ll2020_sE1.jpg

I made a couple more changes based on the UEGO readings I'd been measuring, to lean out the mid-range fuel circuit a tiny bit and move the fuel that would have been wasted there to the pilot circuit. Today's ride confirmed that there's no appreciable drop in mid-range power and low RPM operation is that much better. It's ideal, in fact. Wow! I am really pleased.

Didn't change the SuperTrapp at all. I like it just where it is for unrestricted throttle movement. Which was why I adjusted the fueling. The mid-range was going completely too rich in some WOT RPM scenarios. The leaning now makes WOT available at any RPM without power loss due to over fueling.

It's also confirmation on what I've said to others about their ZX-9R dyno sheets. This is a RAM air motorcycle. You cannot measure how it will perform in the real world by feeding it static air pressure strapped into a dynamometer and adjusting its fueling based on what the dyno computer kicks out. Those numbers are crap and the UEGO proves it!

Many, if not most, SuperTrapp owners might benefit from this little explanation of when to and when not to use Ethanol-free fuel (E0) or E10 ethanol enhanced pump gasoline. If you have carburetors and a SuperTrapp, this should interest you. Yeah, there is a difference that's more than what most of us are being told online.

https://www.youtube.com/watch?v=cb3rtDa8fY0

Looking forward to taking the bike out again soon to see what λ (Lambda) values she'll show. Not actually expecting any surprises, but confirmation.

According to the YT dyno tuners, I should be seeing a 0.75 - 0.77 λ for maximum power or 11.0 - 11.25:1 on the previous pump gasoline AFR scale. I'm thinking that's not going to be the case for this bike. It definitely appears to pull strongest at nothing less than 12.2:1 on E10 pump gas, and 12.6:1 when the tank was mostly ethanol-free.

AEM's table translates 12.2:1 AFR to ~0.84 λ. Today I was seeing 11s for lows at the higher elevations rolling 6th gear past slower traffic going uphill. But knowing what I was doing, I'd roll out a touch to get the AFR back up into the low 12s where power was better.

Steady cruise was bouncing around 13:3 - 13.5 on the highway @ 75 MPH. Still a little on the rich side due to the residual E0 mix. But I added 3g of E10 before returning home, so when I ride next, by the time I get rolling on the highway I'm hoping to see 0.92 - 094 λ at cruise or what would be 13.5 - 13.8:1 E10 AFR.

But the beauty of λ is that it doesn't anticipate whether I'm running E85, E10, or E0. To it the λ output will be the same due to the voltage coming from the O2 sensor. So if I want or need to stretch tank range to 100% maximum, I just have to hold 1.0 λ in 6th gear. And if I'm passing or accelerating, I'm hoping to confirm that 0.84 λ is the sweet spot.

But the shocker for me still is how much more power my SuperTrapp bikes have when ridden on the street than the bike I purchased with the Muzzy CF can. It's so cliche to say there's no comparison, but how else do you put it? With the SuperTrapp, I'm able to ask for any throttle setting and get power. Not so with the Muzzy bike. I don't think that's too much to ask when opening the throttle. The bike should accelerate, but the Muzzy bike must be 10 HP down. What am I saying! It's probably more than that, at least in the mid-range.

The SuperTrapp makes my 900s feel like Ducatis in mid-range punch, whereas the Muzzy makes my other 900 feel like an overweight 600.

I'll keep working on it, but you know how it is when you have a choice to make before a ride. You choose the bike that's the most fun to ride, the one that can handily lead other bikes, not one that's going to be an embarrassing basket case unless you wind it up like a 600. And that Muzzy exhaust note is for the birds too, that slappy senior citizen on energy drink sound. It's all name recognition, with no actual HP engineering behind it.

https://uniim1.shutterfly.com/ng/ser...p_se1_2021.jpg
https://uniim1.shutterfly.com/ng/ser..._ride_2021.jpg

Time to buy my third SuperTrapp, I suppose.

We had ridden one of our staple mountain summits today, then headed into a small town for lunch. While there, motorcycles passed by here and there. Some stopped, then left. But this one guy showed up on an Aprilia RS-V4. Not sure what year, but it looked newish and had ABS, so probably like this 2020 model.
https://www.webbikeworld.com/wp-cont...rsv4-rr-03.jpg

We made pleasant chit-chat with him and invited him over to our table in the shade where we were lunching. He was headed towards the summit we had just ridden and we were headed home, but plans changed. He seemed like a really nice fellow. A little gray haired and by the looks of his tires, he had really wide chicken stripes. So why not give him a show and humble him. He was a former GSX-1000RR owner who loved the Aprilia after he bought it and sold the Zuk, because the Aprilia was all he really needed to get his thrills. 200 HP, fast as f*#@, faster than the Zuk, handles like a dream, ABS and TC. This is the bike to own, he said. Even took it to one trackday at Laguna Seca.

Nothing too impressive thus far, but nice conversation. Looking at the guy you’d assume he was your accountant, not a weekend sportbike warrior. He was in full leathers and did have a little damage to his pucks, but the tires!

I was on the sF1 today after an aborted departure on the sE1. There was a minor coolant leak, of all things. So I parked the E and mounted my other 9R. I wanted something with power and the Muzzy E1 wouldn't cut the mustard.

Timing had it that I was the first to get on the road, so I lead going back to the base of the summit, my buddy behind me, the Aprilia rider behind him and our third rider who loves joining our rides, but not in a spirited fashion, playing sweeper.

No surprises getting to the base. I waste no time taking off at a spirited pace, even up to extra legal speeds. I’m in my rhythm cooking along. That should do just nicely, I thought. It always has in the past. No way that guy is anywhere near me. True, but neither is my riding buddy. A few more corners and my riding buddy is up with me. No. Wait. That’s the other fellow. He’s passed my buddy and on my tail at my pace. Uh-oh. Thoughts change from sacking some innocent dude out for a ride, to we’ve been sandbagged.

This guy rides at race pace. I wave him through on an uphill straight and he literally takes off from me into triple digits. We’re on a short uphill straight that then jibs to the left and right up this canyon. So I give chase. I’m in 6th gear not doing triple digits so he’s still pulling on me, but after the corners he slows down a bit, like down to about 75 MPH so me and my buddy can catch up to him again before he reaches some tight stuff ahead. He’s playing cat-n-mouse with us.

Okay, so I’m willing to turn it up a notch too. Let's see how he does in round two. The tight stuff is up the mountain another couple miles. Let’s see what happens when he gets there. We get to the good stuff all stacked up nicely then he takes off again up to about 90 MPH heading into a 25 MPH corner. Holy crap! That’s not my pace, but I smoke it in too. He’s knee on the ground, smooth as silk through the right-left-right-left complex and I’m in 5th gear losing distance on him. Ahead, there’s a car that slows him briefly on a short straight. He blows past the car and dangles his right leg like Valentino Rossi into the corner before dropping the puck down. Seeing more riders coming up behind, the car pulls into a pull-out and lets us by. I don’t leg dangle into corners, so I just drop the puck, but his pace is too much! He’s gapping me already by about 60 yards. On up the mountain, with me and my buddy in hot pursuit we go until finally he gets stuck behind another vehicle into a slow blind corner. He’s able to make a break for it just as we come up upon the slower vehicle, but he has the jump on us. I go past and so does my KTM-1290 buddy.

We bunch up again immediately after. There’s a couple miles of sweepers that aren’t challenging, so we’re all cooling our heals behind the crazy but skilled old guy on the Aprilia. He's doing leg and arm stretches as we meander along, like that's just what he does in between.

I think, let’s see how he handles the downhill stuff on the other side. We get within about 1/4 mile of the good twisties going down and he again takes it up to about 90 MPH heading into a 35 MPH blind RH corner. He slows and I close in on him, but he accelerates away again to speeds I’m just not comfortable with going into blind downhill corners. It had just rained the night before and there was sand and gravel already observed in some of the corners. I'm not looking to go to the hospital today and my best isn't enough today. This could get ugly with the right wrong circumstances. I keep my pace and my buddy disappears behind me.

On down through left and right turns he’s again pulling away, stretching out his lead. By the time we’re midway down, he’s already pulled about 150 yards on me. Then he appears to slow a bit for whatever reason and I’m able to maintain the gap until the road opens up to straights again.

This time he slows way down and holds his speed. Thinking he wants me to take up lead, I maintain my pace on down the straighter sections of the mountain. He chooses to follow me to the bottom this time. It's just the two of us now. I could see there was a slower vehicle up ahead that would complicate the tight canyon corners near the bottom, but stopping would only provide for a gap at the cost of stopping in hot conditions (and I'm working out, sweating a fair amount), so I press on. I give it my best shot, but he’s right with me the whole way leading up to catching the slower vehicle. I have an opportunity to pass, so I take it, gapping him in the process, because he was left without room to come with me.

When we reach the bottom he turns his bike off and comes over to look over my bike, but doesn’t say anything before remounting his bike. We regroup and I compliment him on his extreme pace. I’ve ridden with a number of riders over at least the past decade and I’ve never seen anyone ride with such smooth surgical skill at this level. I jokingly tell my riding buddy, you follow him and I’ll follow you this time.

We set out in the other direction back over the mountain after everyone checks their fuel status. All good, we head up. Our Aprilia rider wheelies as he straightens out onto the roadway. This time though again, he’s not quite as aggressive, saying later he felt like his bike was sliding, so we’re able to hold onto his pace in the lower canyon stuff and on up the hill. An RV balks our pace just as we get midway up the mountain starting the tight steep stuff going up. He pulls around the RV as it moves over without wheeling this time and both of us are past too. My buddy wasn't fast in this section earlier and he wasn't fast now. He's holding me up a tad, letting the Aprilia rider gap us a little going up into a slower section. Then like a light switch, my buddy turns up the pace to the point that I’m having difficulty keeping up with his 1290.

We’re all flying up the mountain in order of fastest first and slowest, last, me. I’m at 9/10ths pace in 5th gear. When we get to the slower LH RH corners, I'm able to claw back on my riding buddy, but the Aprilia rider has once again gapped both of us easily by about 100 yards. I counted at one point and he was 7 seconds ahead of me. That’s a lot for such a short distance traveled. This guy isn't your run of the mill sportbike rider.

More of the same as we continued to the other side. Once at the junction he stopped for a brief chit-chat before we said our good-bye’s. We had to wait for our third rider to come along. He again gets off his bike and walks over to have a look at my bike, looking at the front, looking at the back. I suppose he's never seen this model Kawasaki before. He asks me, is that a 600??? No, I reply, it’s a ZX-9R, 900. I wasn’t prepared for his question or I would have thrown in, it’s the carburetted California emissions model from 2002, but hopefully we’ll meet up with this rider again in the future, now that we recognize him and his bike. Then we can fill in the gaps if needed.

https://uniim1.shutterfly.com/ng/ser...nhance/600.jpg

Again I compliment him on his smooth fast pace and he appeared humbled by my gushing praise. He said he rides this mountain 2 - 3 times a week, but today’s pace was probably the fastest he’s ever ridden it. His pace isn’t normally like this, he said. I’d hope not! Going off any of the corners on this mountain at the speeds he was doing could turn out badly.

We said our good-byes and off he went. Later, our threesome regrouped for some refreshments outside in some nice shade, the breeze cooling what our icy refreshments didn't. I told my KTM-1290 buddy he’s been sandbagging me. He replies, not really. I was riding faster than I cared to today. It wasn’t enjoyable for him, not how he prefers to ride. Our pace is typically spirited, more flowing and fun, but today it felt like we were racing, cards on the table.

If so, the Aprilia rider won going away. I could make excuses, but the SuperTrapp shod ZX-9R performed mightily today. It just wasn’t enough under my stewardship.

Tripped reserve at 210.7 miles on the way home from four gallons, dented by the unusual pace. One top off at the start of the day and nothing after for the sF1. Not so for my two riding companions. They had to refuel their KTMs twice more after their initial top off.

Quote:

---

Originally Posted by kz550

... Yeah, he says, about two weeks ago. I spoke to him this week and he said he sold it. The H2 is gone.

No way, I reply, thinking here we go again! He sold it?!...

---

The story my friend told me wasn't true. The H2 rider hasn't changed bikes. I ran across him on a ride in the mountains, so I don't know if my buddy was mistaken or pulling my leg, but neglecting to tell me the punchline.

I'm actually very pleased to know the H2 rider hadn't sold his beloved bike. It gives me hope seeing other motorcyclists riding the bike they love. It's a brotherhood.

https://www.zx-9r.net/images/smilies/vdance_smilie.gif Supertrapp motorcycle slip-on installation how-to. Replacing that awful Muzzy!

Preliminary AFRs indicate it's a whole new ballgame. In the 1 - 4K RPM range, everything is max rich now.

I have to complete the installation of the muffler, which entails having the brackets welded on. Then the muffler will be held firmly and I can begin power tuning on this third Supertrapp endowed sportbike as well.

I had some peculiar issue with the operation and reliability of the bike. It was hard to diagnose. She even stranded me outside of town one night some months back. Fuel pump issue, again. Most said electrical, maybe 22 y.o. wiring starting to go bad and I was one of them. But I love riding this bike too much, I wasn't going to give up that easily. I couldn't understand what was killing my fuel pumps. The first OEM lasted 110,000 miles before it gave up. It was hit or miss on rides, but I couldn't go a couple ride seasons without one expiring and after putting in a new model, the bike still didn't feel happy. So, I rightly thought there was some other electrical gremlin nagging her.

Never underestimate the requirements specified by the engineers!! Turns out after the last one blew out, that I was able to refurbish the original Mitsubishi fuel pump with new OEM contact points. The bike was instantly transformed! It's been about 750 miles since then and nothing but gravy, the bike has never run better! Of course, it's the package deal; everything has a hand in it: Supertrapp, AEM UEGO, Keihin carburetors, Mitsubishi fuel pumps, TourmaX points, and the general overall operation of this now again ultra reliable Kawasaki motorcycle. I just needed that one key OEM component working, cutting off at the proper fuel pressure and drawing the correct current.

So what happened beyond just that? Her 150,000 mile milestone was within 229 miles and I wanted to eclipse that mark as a gesture to putting the nasty odd behavior she was experiencing in her rear view mirrors from 'made for' fuel pumps. So with little fanfare other than a camera, I set out to get in one last long ride before the weather changed permanently.

https://uniim1.shutterfly.com/render...&ts=1635558609
https://uniim1.shutterfly.com/render...&ts=1635558611

It was a lovely fun ride, despite some cold wet sections of road and having to navigate snow lined highway, but it was worth it. Just loved hearing that potent Supertrapp crackle and roar and taking in all in on my favorite bike of all time, my ZX-9R sE1.
https://uniim1.shutterfly.com/render...&ts=1635558603

But in my distracted state, I kind of blew it on fuel stops. I was way beyond the bikes r/t service range and I should have picked up fuel on my way back, but I kept fooling myself, without proof of what my final range would end up being, that I could probably divert to a gas station before town. No worries. Keep going!

Mileage piled up to the point where she had been tripping reserve like clockwork over these past two riding seasons. Only she didn't. So I checked the fuel tap position: ON. No worries. Continue on, she'll let you know. She did trip reserve a bit high on the last ride as well. It was probably a fluke though. Soon the odometer had clicked off ranges I'd only seen a couple other times before reserve was tripped. Okay, I thought, maybe the tap straw for the ON position just happened to pop loose. No worries, there are still gas stations in between, just a lot more expensive due to their remote locations. On we went until all previous personal records were now dispatched. She really had me worried, but then finally she tripped. I could smell cockpit fumes, which is her way of letting me know it'll soon be time to flip to reserve.

Needless to say, I didn't have to divert along the way for fuel, I bet on her backing up her range capability on what was in reserve. And she did, with flying colors. Topped her off to verify distance, then Google mapped the route to back up the odometer and fuel receipt.

Mind you, this wasn't a range run, it was a fairly typical ride, including passing slower vehicles in passing zones going up hill, some long idling stops, canyons and mountain twisties, all the usual stuff we typically do, at close to the pace I typically ride at. I say close to, because the road conditions at this time of year weren't conducive to full pace in some areas (snow, sand, moisture in shaded corners, etc).

So now, I need to run the UEGO numbers again, collect the new data stream. It'll be the standard by which my other two Supertrapp bikes will have to measure up to.

Nothing too Earth shattering about the AFR numbers, from what I can tell. I've watched them repeatedly so it's ingrained in my memory. I think I was expecting something very different from the readings just based on seat-of-the-pants feel. No exciting headlines though. AFRs move predictably and consistently. For sure, the readings are not what I expected from the outset, nor from what I've seen dyno tuners use while tuning other bike engines.

If I had taken my bike to a dyno tuner at any point along my journey of bike ownership, I'm certain the results would not be anywhere near like the results via Supertrapp FAQ and then elevated by way of real-world UEGO readings.

The experience has taught me so much more than I imagined. Surprising as it might seem, to learn more, wasn't the original goal. It was to record what I thought was a perfect tune at the time, a tune unlike how she's now tuned. The UEGO told me things that only it could, that my 'perfect tune' of three years ago, could be better and that different fuels require different ideal jetting. Which meant that I couldn't leave well enough alone until I went down the path it lead me to discover for myself. RAM AIR motorcycles are difficult to tune via dyno, if not impossible. The dyno environment with an oxygen sensor probe stuck inside the tailpipe cannot reflect how the building air pressures effect AFRs. They can only tell the tuner how the bike performs from unrealistic negative airbox pressures. The O2 readings alone are so far off, that to use them to make jetting predictions, is a fools errand.

Don't read into this that my ZX-9R's current tune is a game changer for peak HP numbers. It's not. Sure, the bike is quite powerful, but ultimate top-end was never my goal. I feel the pinnacle of endurance street/canyon carving tune for my bike has been achieved and there's nothing more to learn from observing the oxygen readings coming off the bike's exhaust. I'd much rather just enjoy riding it on the street now.

https://uniim1.shutterfly.com/render...&ts=1621348322

This one, the one I just put a Supertrapp aluminum racing series 2" ID x 13" L x 4" OD on.

https://uniim1.shutterfly.com/render...&ts=1639360198

Had quite the weekend with this bike's carburetors in below freezing outdoor temperatures in a garage with doors cracked to allow ventilation for gasoline fumes. This bike came to me as a third owner bike that looked wonderful on the outside but was basically a butchered mess on the inside. I doubt the second owner did any of that, he didn't seem like the mechanical DIY type. The original owner had dumped some money into it, from obvious inspection, that the bike was a trackbike with lights. One of the major issues I'd been having with it was the carburetors or perhaps exhaust flow. With all of those component settings and options exhausted, the last ditch item must have been the old exhaust muffler. Thus the Supertrapp, which I thought would be my last possible option in restoring the bike's power from idle to about 3/4 throttle. When that didn't do the trick, I knew it had to be an issue with how the carburetors were modified and I was right, finally!

Fortunately for me I had a spare set of decade old unused carburetors that fit my bike. I had purchased a rebuild kit from Parts Unlimited that was an OEM match, so I simply needed to drop in the stock parts from the modified carbs that were on the bike and use those settings as a starting point. In the process I finally saw what had been done to the working set that came with the bike. They'd been modified with a race kit from Factory Pro for the 49-state version of my bike, not my version, which is made for California. The CRB-K88-1.7-RK, 'race kit' wasn't a fit for the bike, even though there's a case study by a shop in Oregon on FP's Web site of doing exactly this modification to exactly this bike model using the 49-state race kit.

They start by saying Peak HP was 131.6 on the dynojet dynomometer and end up saying YEEE HAAA! What do you know.... 144.7 HP! 13.1 HP gained on top and significant gains throughout the RPM range above 5K RPM. I think this was what the original owner tried to emulate. He modified the carburetors exactly as that shop did, less the pilot jet increase. He replaced the stock exhaust with a full Muzzy exhaust, pulled out the main air jet and put in the RK air jet from FP, all basically the same as the shop did, but wow, did it fall short of expectations!!! The bike falls on its face off the line, like I said all the way up until about 3/4 throttle and 7,500 RPMs, when it finally comes alive. I bagged that set of carbs and returned them to the settings I found them at. I'd experimented with all of the possible combinations of components and while I'd see some hope in making one area better, another would go to crap. ENOUGH! As a race set of carburetors, they'd probably be okay. But I don't ride track, so it is of little use to me.

The other tidbits I'll add about the Factory Pro case study was that their 2000 ZX-9R was shop tuned in Hillsboro, OR, which has a base elevation of basically sea-level, 194' AMSL. The motorcycle's owner, Jim Gilbert of Ashland, Oregon, lived at a base elevation of 2,000' AMSL. It's a carbureted bike! You don't jet a carbureted bike rich for sea-level and send the owner up into the mountains with it! JHC! You have to detune it approximately one step for every 2,000' in elevation. Kawasaki recommends a reduction of 4% for 2,000' AMSL and 8% for 4,000.'

The shop tuner noted “customer complained about terrible "lean surge" at cruising and low speeds when he brought it in.” Which, as any ZX-9R owner who knows anything about their bike or has asked other owners online about it will tell you, is a simple combination $1.00 fix with a throttle body synchronization and pilot fuel screw reset. You add a 0.5 mm shim (washer) under the stock jet needle to effectively raise it, synchronized the carburetor throttle bodies, and set all of the pilot air screws to OEM turns out. PROBLEM SOLVED!

The stock settings on a 2000 ZX-9R are: Pilot Fuel Screw 1 5/8 turns out, #38 x 4 pilot jet, 4 mm +/- 2 mm float heights, N9BB jet needles on a standard 0.6 mm OEM wear washer, and a #160 out/#165 inside - Keihin main round jet stagger. The owner had already modified the main jet stagger however prior to dropping it off at the shop, putting in #165 out/#170 inside, an increase of 3% equally on all jet sizes.

The shop apparently missed that fact, one of many. They bumped his #165/#170 main stagger, calling it “stock,” with Factory Pro reverse staggered #178/#175 mains, a bump in fuel delivery of 8% on the outside cylinders and 3% on the inside over the previous jetting and 11% on the outside and 6% on the inside, over stock. They don't explain why they did it this way, but may have concluded incorrectly that Jim's ZX-9R was a 2002, which does use reverse stagger main jets, with staggered jet needles, as well. Factory Pro doesn’t mention reversing the stagger either as the way to install their RK race kit. But they didn’t point out the oddity either on their Web site. On top of all the other richer settings, the shop also bumped Jim's ZX-9R pilot jets 5% richer, from #38 to #40. Lastly, they installed an Akrapovic full exhaust system.

Neither the shop nor Factory Pro caught any of the problematic tuning errors: not the glaring elevation error, raising fuel delivery on a bike whose base elevation is 2,000' above where it is being tuned nor the compounding of larger than stock main jets nor the reverse stagger errors. But that's all beside the point. The shop showed a 10% gain in HP from their near sea-level elevation dyno. Which is either a false flubbing of some corrected dyno result numbers or a brilliant discovery. Jim was sent home with his tuned-for-sea-level carburetted sportbike with the oddest jetting configuration I've ever heard of, outside of some DIY horror stories. :confused: http://www.factorypro.com/prod_pages/prodk88.html

I would love to speak to Jim Gilbert to see if he loved the bike and still owns it. However, there is no record or follow-up to the story that I can find. Which is kind of odd in this day of Internet and social media chit-chat. Yeah the shop work was from 2000, but this is the pinnacle case study used as the benchmark of all benchmarks! Other than a final dyno run, we have nothing further to confirm the veracity of this monster tune that somehow turned compounded errors into massive results.

Moving back to my project though. I installed the used spare set with the same best-of settings as were on the FP set of carbs and the results were immediate. Better throttle response and power. Easier to get the bike off the line. Not perfect obviously. And this is where the UEGO comes into play again. There's no guesswork in what needs improving. I cannot diffuser my way out of this with my Supertrapp alone. The UEGO showed me where my initial jetting is deficient, so I know what I need to try next. I might even need to adjust in or out some of the Supertrapp diffusers too.

Super satisfied at the moment. Started the day with some blockage in the spare set of once dirty carburetors I recently installed. One or two of the pilot circuits, maybe all of them, according to the UEGO, were clogged. Was getting 17s at idle this morning and the bike not running too well under 2K RPM.

After taking the bike out to visit with friends, I brought her back home for a cleaning of the pilot circuit. Ran the bike to almost a stall pulling into the garage. Wanted to drain the fuel out of the float bowls, since the carbs were coming off. 1-3 bowls were empty. #4 had fuel. Bingo! Could have been dirt in the pilot air jet at the mouth. Took several shots of carb cleaner before it was blasting out the pilot jet cavity like the others.

Slapped everything back together for a synchronization and idle speed test to verify the cleaning worked. The throttle bodies were enough of a mess that synchronizing them cured the rest of the idle weirdness. Overall jetting still is not perfect, but this isn't even the same bike anymore, way way way better and that slappy Muzzy exhaust note is GONE! My Supertrapp is just roaring! Sounds wonderful! A lot more power throughout. Easier to ride, absolutely no hint of stalling. Decent mid-range and this bike's got some grunt up top too, like I've never seen from it. She's pulling the front wheel off the ground by 8K RPM. And I can see by the UEGO she's not right yet while doing so, low 11s on the gauge, about 1.0 - 1.5 AFR too rich on the main jets.

There's lots of room for improvement, so... it was a good day! Not like before though with the Factory Pro jetting and Muzzy muffler, where the bike felt like it was a lost cause. Now I'm trying to determine if the improvements that remain might be restricted by the Muzzy 4-1 headers or if I perhaps mistook the cams for being stock when I looked last. But who cares, right? I'm just beside myself. Today felt like a giant leap forward. Kind of reminded me of some of the early days with my other Supertrapp ZX-9R, when I was questioning how long I'd keep it, because I didn't think I had the skills to make the bike better. Then after keeping at it, she just snapped out of it and became a dream to ride.

So it goes to show. Don't doubt the unknown. Keep driving forward. I was second guessing myself as I was digging into the bike today, due to all of the failed effort put in when it had the previous set of modified Factory Pro carburetors. This was the shot in my arm of confidence I needed. So telling myself to be thorough and accept putting in additional effort today when I could see the carburetors weren't right; like #4 paid off. 1 - 3 got a cleaning too, because I was already invested with the carbs off the bike anyway. Couldn't hurt to put in the extra 15 minutes to do all four, instead of the one that absolutely needed it.

Flying high tonight!

The primary goal has always been to get this bike to perform and secondarily make it more civilized than it is at the moment. I can report that I'm getting closer to one of the two goals, which means the second won't be far behind.

Right now, I have about 16 diffusers stacked on a 2" ID aluminum racing series. Unfortunately, Supertrapp doesn't mention this, but the small inlet series mufflers are also shorter than the bigger ones. At least, that's the way it is between the 2" and my other 2.5" ID mufflers. So, being that the muffler is smaller and has less internal volume, it's also significantly louder. But I accept that for the performance and observance of motorists on the road that I'm getting in return.

After the last major leap forward with the spare set of carburetors I owned, I adjusted once more to settings only slightly leaner. And with the help from my wide-band UEGO, I was shocked to see how sensitive the bike was. I was not prepared for what I was seeing. The bike was showing undesirable AFRs and letting me know that the main jets were still too big. So, I quickly returned back home and split the difference of the two changes I'd made, putting the washer shims back in under the jet needles, but leaving the pilot fuel screws at 1 3/8 turns. In this setup there is a lean flat spot around 2.5K RPMs and at WOT the mixtures are probably 4% too rich, but power and performance are closing in on my preferences.

At the moment, the bike feels like a 700 below 5 - 6K RPM. Not bad, but not like my other two Supertrapp ZX-9R Ninjas. Above 6K, the bike goes a little mental and feels more like a 900 or 925cc Ninja 9R. I rode it several times this weekend in a mix of street and highway conditions and I can definitely live with these settings. The bike is a little loud still, but when I have more time, I can address the main jet richness issue and revive shifting fuel around to the other carburetor circuits to really dial her in.

What confounds me though is how many people are so convinced that jet kits are better than just rejetting using factory replacement jet sizes. And in the case of the original owner and the case study of a Factory Pro "race kit," touting monstrous power gains throughout the RPM range, I am at a loss for what got lost in translation. I wasn't there to see how this bikes' projects were undertaken, obviously, but what a freaking disaster and waste of money and effort. There's really only a few possibilities to consider.

1) the bike may also have aftermarket cams? That could be true. But the cams appear to be stock, even though the engine does feel peaky.
2) whomever performed the race kit installation drilled or modified the original 50-state California EVAP carburetors incorrectly?
3) neither 1 or 2, the Factory Pro Race Kit, which is designed for the 49-state ZX-9R, does not work right with the 50-state model carburetors, as claimed in the case study?
4) none of the above, the race kit doesn't live up to its claims, which seems impossible given the number of people who have claimed otherwise.

I sure would have loved to take ownership of this bike where it did have monstrous power due to the race kit, just so I could have experienced what others are so brand loyal about with aftermarket jet kits. But on the flip side, any one of us could be deceitful or unable to recognize improvements from a step backwards. When you have a UEGO there is no compelling reason to do so, simply because whatever goal you're after, it'll guide you to it. You won't have to lie nor settle.

When it's time again, the next step will be to lower then main jet one or two steps, bump the JN into the 0.8 - 1.0 mm range and take off four to six Supertrapp diffusers.