KLX300 won't start, oil fouled spark plug


2 weeks ago I road my bike for several hours on the trails. After the ride, I parked it in the garage with the fuel off and didn't touch it until today.

I went to start it and for 10 minutes of kicks, it never once gave any indication of a spark.

I took the plug out and the end was coated in nice dark black oil (if it matters, I just replaced the oil prior to my ride 2 weeks ago, so the oil only has a few hours on it and maybe 10 miles in relatively dust free riding).

I searched the forum for "oil fouled spark plug" and a few other variants and didn't find anything.

I also checked the valve clearances and they are within specs.

Any thoughts on what might be causing this?

Did the bike start with a clean plug?

Exhaust smoke on accelleration = bad rings

Exhaust smoke on deccelleration = intake valve seals

Ride on


If I can get it to start I'll have to keep an eye out for smoke on acceleration / deceleration.

I didn't notice any smoke during the ride a couple weeks ago, but admittedly I wasn't looking for any.

Thanks, Mike

Ok, I'm a dolt. The black oil was actually soot that had mixed with gasoline. Some how the engine flooded. Oh well, in the process I checked the valve clearances, cleaned the carb, checked the gap in the spark plug, and a few other general checks.

Thanks for the reply, Mike

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