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Oil in the head

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I posted this in the CRF50 forum, but I figured I'd post here as well since this is a general question:

My buddy came over last night with his 04 crf50. He asked me if I might be able to help him fix it. He says the motor is cutting out when he has it under a heavy load and is riding it through choppy terrain. It was late and dark so I could not test the bike myself, but we decided to check a few things. The plug looked fine... a little rich but not too bad. He cleaned the filter. I decided to take a quick look at the valves. When I took off the bottom exhaust valve a bunch of oil poured out onto the floor. I would say approx 1/3 of a cup of oil. I didn't think this was normal so I looked at my CRF 50 and no oil came out of the exhaust valve on my motor. Can someone tell me if this is normal? If not, any thoughts on where the oil is coming from and how to fix it? Any advice is appreciated.

Thanks!

Pat.

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You're right, that's definitely not normal. I know nothing about CRF50's but, if I were to guess, I'd say that the valve seal(s) were bad. Take a look at the valves too to make sure that they're not worn down making it impossible for the seals to keep the oil out. The guides could be worn too.

It sounds like you'll at least have to have the head re-worked if not replaced.

Best of luck. :cry:

PS: The only thing I question though is how the plug would look fine and how it would run at all if it's getting that much oil into the exhaust. My first guess, prior to the oil in the valves comments, was that the plug was breaking down or possibly the coil. :cry:

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PS: The only thing I question though is how the plug would look fine and how it would run at all if it's getting that much oil into the exhaust. My first guess, prior to the oil in the valves comments, was that the plug was breaking down or possibly the coil. :cry:

I was thinking the same thing about the plug... I was thinking it was something electrical. I figured I would quick check the valves since they are so easy to do on this bike and that is when I saw this. it does not make sense to me... Then again.. I'm a computer guy NOT a mechanic. :cry:

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you mean the valve cover? its normal for oil to be under the valve cover on a four stroke. if there is no oil geting to the head the cam shaft wold siez. where you don't want oil is the combustion chamber.

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you mean the valve cover? its normal for oil to be under the valve cover on a four stroke. if there is no oil geting to the head the cam shaft wold siez. where you don't want oil is the combustion chamber.

valve cover is right!....Sounds to me like there is an obstruction in the port that lets the oil drain back into the trans. If its still under warranty take it back to the dealer! If not you will at least have to pull the head off to inspect.good luck :cry:

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Man you guys really dont know 50's :cry:, the bike is fine and that oil pooling there is perfectly normal, its just the design of it. Like the other guy mentioned, the problem is the float in the bowl. You boys just step back and let the mini experts take care of it :cry: :cry:.

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