RPM Fluctuation


New Member
FZ1 enthusiasts:

My 2003 FZ1 has an issue where the engine RPM is fluctuating on acceleration. It's most noticeable in the 3,000 to 6,000 RPM range, but it's definitely there higher than that also. It gets worse if I've been out on the bike for maybe 120 miles or so in a day. I haven't dug into this problem deeply yet, and I don't know the bike very well yet, as I have only had it for a little over a year. The bike came to me from southern California with a lot of miles on it (about 97k) and many pages of maintenance records. I'm thinking about things like ignition coils, spark plugs, spark plug resistor caps, fuel pump, fuel petcock, vacuum leakage, EXUP system, and carb syncing. Does anyone have advice on choosing a starting point?