I have a XF200 I purchased used (with 200km on it). The person who
originally bought it installed a FMF Turbine Core 2 exhaust on it. The
bike runs rich and bogs only at full throttle and fouls out the plugs
pretty quickly. I thought the previous owner might have put a bigger
main jet in but when I pulled out the main jet it was a 125 which I
believe is stock (or close to it). Shouldn't the bike be running lean with a bigger
exhaust under these circumstances? I added a 132.5 main jet and now it
cuts out at high throttle so appears that it's running even richer
now. I am going to put in a Moose air filter to increase airflow as my
next step and go back to the 125 main jet. Do you all have any other
ideas? One other issue I am having. When I removed the main jet there is a washer but I cannot get the jet back on with the washer on, the jet is not long enough. Thanks