- Jul 18, 2007
:bang: I’m am having a problem with my 1993 RM 250, when I start the bike and try to take off after putting in gear it bogs down and loses power, I have checked everything and at first thought a may have been a spark problem and cannot find a simple solution. I have an FMF Fatty pipe with Boyesen power reeds, Keihin 38mm carb with 52 pilot and 185 main jet the carb has been cleaned and , new cdi unit, spark plugs, compression 155 lbs when hot, did leak down test and held pressure for one minute. If I pull clutch in rev and let out I can slowly give it gas and get it moving but with uneven acceleration and will not go into power band, starts cracking up. I bought this bike with what the previous owner who thought this was a carb problem. I found a vacuum leak that I fixed that enabled it to start easier. When the bike stalls after bogging it can be started on the first kick. I am unsure if the bogging is from too lean or too rich.What is a good stating point for jetting sizes with this configuration .Any suggestions would be appreciated.