I have a 92 cbr900rr. My bike fouls plugs on start up. generally the day after city riding.the bike has done 60 000klm i have been chasing this problemsince 30 000klm. i have paid bike shops to tune it, i have repaced the carbys and 2000klm ago i had the motor rebored with new seals and gaskets. the bike is fine if i ride it on the highway but if i ride itaround town it won't start on 4 cylinders the next day. any help would be much appreciated.

 

start up with less of a choke, dont throttle when choke is applied. check Spark plug gap. if possible throw a spark tester the inline type with a light on it.on it make sure you dont have a wire making bad contact, for the ignintion system.

 

You should probably also have the coils checked. They go bad a little at a time or all at once,