oil in airbox? - Honda ATV Forum
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post #1 of 5 (permalink) Old 06-14-2011, 01:27 PM Thread Starter
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oil in airbox?

I have my 2000 300ex with hmf slip-on, 130# jet, Big Gun rev box, uni air filter and the rest is stock. Well when I was washing her down I noticed in the airbox drain tube on the bottom it was filled over half way with oil. I always keep her clean but dont clean that part as often. I emptyed the drain tube and cleaned really good and did 15min. worth of riding and had more oil in drain tube (not alot but enough to cover bottom). The airbox itself was clean inside, the air filter is new. Could this be from excessive air filter oil? But the air filter didnt look overloaded with oil to me. Any thoughts or help?
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post #2 of 5 (permalink) Old 06-14-2011, 01:33 PM
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Might be slight blow-by out the crankcase breather. To check this pull the crankcase breather off the bottom of the airbox and see if its blowing oil out there. Might have to put the motor under a load such as power braking it. Also check the oil level, if its over filled it will do the same thing.
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post #3 of 5 (permalink) Old 06-14-2011, 08:12 PM
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Yep,what RW said...Also,make certain that you're using the called for oil weight in your motor...

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post #4 of 5 (permalink) Old 06-14-2011, 08:18 PM
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Is your oil in the right level? may be the pcv valve is clog.
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post #5 of 5 (permalink) Old 06-14-2011, 09:25 PM
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you could do a leakdown test--hook an air compressor to your spark plug hole (you need the fitting) andpressurize the cylinder, this will also tell you if you have leaky valves too. if oils blowing in the tube, you got worn rings/cylinder

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