Oil in crankshaft area

Discussion specific to the 1989 - 1994 (E Series) KDX200 model sold in the USA
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ToXic
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Oil in crankshaft area

Post by ToXic »

Maybe a stupid question or I just really need to hear from somebody else what I already know...
The last time I rode my E4 was 2 years ago just to see how it was running (great by the way), and before that it was parked for almost 10 years... Anyway, I am inspecting and rebuilding the bike, also doing the top end and all that, and I would rather leave the bottom end as it is because it was working perfectly, maybe check the clutch and water pump and that would be it, apart from fresh gearbox oil.

But with the cylinder and piston removed, after turning the crankshaft slowly I see a film of oil (looks like gearbox oil) around the edges of the crankshaft. The gearbox oil quantity has been at maximum level for all these years, so my question is, for all of you that rebuild the top end, is it normal to get some oil in the bottom of the crankshaft case area? Can this be some remnant of premix oil? Or... is this a sure sign of leaky crankshaft bearing seals?...
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SS109
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Oil in crankshaft area

Post by SS109 »

If there wasn't oil in there I would be worried! Yes, there should always be some 2T oil down in there.
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Re: Oil in crankshaft area

Post by KDXGarage »

That is normal.

When the fuel enters the cylinder, the oil drops out of suspension and ends up down in the bottom of the engine. As the crankshafts spins through this pool of oil, it flings some upward onto the cylinder walls, bearings, metal surfaces, etc. to provide lubrication. The depth of oil pool is a way to measure proper quantity of oil in the fuel.

No oil would equal no good!
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ToXic
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Re: Oil in crankshaft area

Post by ToXic »

Thank you for your answers, that is what I thought but after reading about some leaky crankshaft seals I wanted to make sure that what I was getting in there was normal - this is the first time I am tearing this engine apart :)
Time to install those new crankcase studs and a clean cylinder :)

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Re: Oil in crankshaft area

Post by bufftester »

Yeah, if your crankcase seals were shot it wouldn't be running great.
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Oil in crankshaft area

Post by SS109 »

Leaking crank seals would show up via 2T oil in the stator area on the left side or leaking on the right by losing transmission oil, excessive smoking, and fouling plugs. Both will cause poor running conditions.
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