Sport Exhaust muffler for 1992 K75; will it work with Fuel Inj?
I want to try a sport (louder) muffler for my K75; but I wonder if it will affect the fuel injection mapping.
I'm afraid it will lean out the mixture and over heat the engine if the fuel injection is not able to handle the reduced exhaust back pressure factor. I have a MACS glasspack slip-on muffler made for this bike, but don't want to hurt the engine; I just wanna hear the little 3 cylinder wail!
L-Jetronic is not a closed loop system. Just bolt on the new new muffler and wail away. I have a '87 K100 and years a go I pulled the stock system off both head pipes and muffler. Bolted a complete Supertrapp system in, didn't do any other mods. Ran it over a year with no problems. Removed it and reinstalled the original exhaust. That wailing away was just to loud for touring.
While I personally dislike noisy motorcycles and wouldn't do that to my bike - it won't hurt it.
Unlike Motronic equipped engines in which the air flow is "computed" based on RPM and throttle position, the LJetronic in the K75 uses an actual air flow meter that directly detects the angle of the meter barn door, thus the amount of air.
So, if perchance the exhaust change actually increases intake air flow (I doubt it will) that increase will be measured by the air flow meter and the fuel delivery will be adjusted too.
Paul Glaves - "Big Bend", Texas U.S.A
"The greatest challenge to any thinker is stating the problem in a way that will allow a solution." - Bertrand Russell
Ran a Luftmeister on my K75P(ichler) and a Remus on my K11RS. No engine issues from either. Tone was nice, a bit louder but not obnoxiously so. I would NOT put a 2Brothers on anything- those are loudly annoying.