Oil leaking

So, rode on Thursday no problems. Gave the bike a thorough cleaning today then started it to let it warm up for an oil change and noticed oil leaking from the filter cover, shut it down. On further inspection oil is also coming from the largest of the breathing tubes and maybe from the seam at the bottom of the head. Lost about 3 ounces.

Details: 2006 450X, it was cold -3C, hard starting cranked for a while battery went low so I kicked it a few times then boosted it. It did have one sharp backfire before it started but upon boosting the battery it started right up. It seemed to run fine before I shut it down but I did notice the exhaust pipe got red fast with the choke on.

Any ideas?

Check the coolant and oil levels.  Sounds like the crankcase is becoming pressurized.   Coolant getting into the crankcase is the first thing I'd check.



How long did you let it idle for ?

It idled for about five minutes. Coolant level is good and no milkyness in the oil, it is clean.

Have you emptied/cleared the main vent tube? The one with the little squishy-valve at the end?

Have you checked for pinched breather hoses?

Have you checked for oil migration from the transmission?

No pinched breather tubes. Oil on crankcase Side is now at bottom line level. Have not checked the crankcase breather yet, will when I'm home in two weeks.

That's a bit of a puzzler then....I think were all assuming that it wasn't leaking from these places before this. 


Do you feel it started right when you were washing it or that's just when you noticed it?   How many hours before that since you last checked the oil?   When you washed the bike, did you lay it over on its side, or prior to that when riding?


Check the breather tube and make sure it's open, but it could be anything.



Very strange problem you have there.

You mentioned that the bike back fired once when you started it.

You could be dealing with a blown base gasket or its possible that cylinder and head bolts might have worked loose cause a leak at the base for air to come in (red hot header) and oil to leak out at the base.

The added air pressure could also cause a spike forcing oil out the header breather tube.

Hard starting is also a symptom of a blown gasket.

Might be worth checking.

You could be dealing with a blown base gasket...



 Good thought...that fits pretty well.



If you have a after market paper base gasket instead of the OE metal gasket then the blown gasket theory is even more likely

Cant verify right now but I do believe the gasket is not metal. Thanks for the advise.

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