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honda_noob
11-11-2007, 01:45 AM
I have a 1991 Honda XR250L with supertrapp exhaust and I have some questions since I know nothing about this. I use my bike primarily for commuting, but do go trail riding some. I need the mpg with some zip for traffic. I currently run with 7 discs. I also have some black spray coming form the seal between the exhaust and the supertrapp this is spattering my swing arm and my fender with black drops. I am having issues with my engine dying while cruising at speeds 40mph and faster, could this be part of the problem?

I would like to remove my snorkel as well, but if I make no other changes to the bike would it do anything, or cause more bad than good?

Thanks for reading, and appreciate the input.

bschultz
11-12-2007, 08:14 AM
I have a 1991 Honda XR250L with supertrapp exhaust and I have some questions since I know nothing about this. I use my bike primarily for commuting, but do go trail riding some. I need the mpg with some zip for traffic. I currently run with 7 discs. I also have some black spray coming form the seal between the exhaust and the supertrapp this is spattering my swing arm and my fender with black drops. I am having issues with my engine dying while cruising at speeds 40mph and faster, could this be part of the problem?

I would like to remove my snorkel as well, but if I make no other changes to the bike would it do anything, or cause more bad than good?

Thanks for reading, and appreciate the input.

The black spray could be considered normal, like when you start a car in the morning. When the exhaust cools down the gases inside the pipe/muffler condense and form water droplets. This condensation mixed with exhaust residue give you the black spray when you do a cold start. This also could be an indication of a rich running condition (excessive exhaust residue).
A rich running condition can be caused by three basic things, to much fuel (jetting), to little air (filter/airbox), not enough exhaust flow (muffler). To diagnose, pull and read the plug (any good car or motorcycle manual will have a spark plug diagnostic page). Generally...Dark/sooty-rich, light/ashey-lean, proper burn should give a golden tan. Assuming your plug indicates a rich burn and your engine internals (rings/cylinder bore, etc) are in good order, you can add discs (to increase exhaust flow). The snorkel removal you refer to I'm assuming is an airbox mod (to increase air intake). These mods/adjustments should cause the engine to run leaner and give you more top end. A rich condition normally doesn't cause the engine to quit, however may cause the it to run flat on top.
To remedy the leak, if it's at the inlet of the muffler, 1) remove the muffler, 2) clean the muffler inlet and the connector pipe, 3) apply a bead of high heat silicone to pipe, install muffler, torque clamp, let set overnite.

honda_noob
11-12-2007, 07:52 PM
I will try your suggestions and thanks for the added information, I really appreciate it. I have allot to learn.