Crankcase oil sucked into piston chamber???


May 9, 2007

This is my first post, I sure hope someone out there can help me.

I have an '89 KDX 200 SR (Japan model with oil injection) that all of a sudden started smoking much more than normal, as well as running as if it is fouling a plug, which it is by the way. Also there is a strange kind of rubbing or strained 'Rrrrrr' sound coming from the engine. At first we thought the injector was injecting too much oil, but then I noticed that the crank case oil was disappearing.

I've never been that far into an engine and would like others opinions of what issue I may be facing. As of now I think that the crankcase oil is bypassing the crankshaft bearings/seals, but perhaps there is another path the oil can travel? If this is the problem, does this mean a complete tear down? Better to just sell the bike and invest in another?

I am an expat living in the Philippines and unfortunately the bike is an import, so there are no parts available in country.

Thanks for the help,


trevor morgan

Mar 15, 2005
sounds like your main bearings have given up, they make a rather loud rumbling noise and vibrations that can be felt through the whole bike at certain revs. This would also cause the crankcase seals to let oil in. Take off the flywheel cover and see if there is any up and down play in the crank, if there is then it means a strip down I'm afraid.

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