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Yamaha 04 YFZ 450 Smokes blue and spits oil out of exhaust

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I have a 04 YFZ450 Raptor and it runs great but recently started burning oil in larger amounts, and smoking blue heavily, but still running great. There was a good amount of oil coming out of the exhaust. I just took the motor apart to rebuild the top end to replace the piston and rings. But to find it was a 97mm big bore piston kit "ESR" and piston looks great and rings look fine. I dont know if it is just the rings or the valve seals to be replaced.

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does it smoke on start up and then clear up or does it smoke all the time?

Smoking all the time is usually the rings

smoking only on start up is usually valve seals.

Best thing to do would be to do a leakdown test, that will tell you for sure

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does it smoke on start up and then clear up or does it smoke all the time?

Smoking all the time is usually the rings

smoking only on start up is usually valve seals.

Best thing to do would be to do a leakdown test, that will tell you for sure

All the time, alot of it, piston and cylinder look good, no blowby on the piston. But one cam has blue color that it got hot at one point. And one exhaust valve spec was on the tight side.

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