KX100 Fouling Plugs

[dstack101]

Although I ride a thumper, my girlfriend rides a 2-stroke KX100 which loves to foul plugs inconsistently......bike starts first kick, runs great for hours, but shut it off then try to to start it......fouled again! Took it in to a local race tech....his reply change oil mix......did it....fouled again......tried hotter plugs......fouled again......changed jetting clip adjustment to make it leaner......fouled again.......good synthetic leaner mix.......fouled again.......perhaps this bike is a four-stroke cause we tried everything short of removing oil from the picture entirely.....................................................................frustrated!

 

[oldguy]

My guess is the carb float is sticking allowing fuel to run in and the overflow into the reeds. When you try to start it up the fuel is so rich it fouls out. Had the same problem with my bike last summer.

 

[LocoCD]

We have had to drop 2 main jet sizes when using aftermarket reeds. The KX100 runs rich with stock jetting, "leaning" the oil to gas ratio will not solve this problem... there is a long and storied history at DRN about how leaning the oil ratio actually makes the bike actually run richer. Do a quick search, it is an interesting topic.