WR450 Oil Blow Out

Hi. First time posting here, got a question about my 2003 model. I re-routed the oil blow by hose that used to drop down under the engine, I piped it into the airbox; had success all summer long, all of a sudden I notice oil is blowing out of it; leaking all over frame etc. I took the airbox cover off, started it up and see the oil blow into the air box while it's running! I've never had any problems with this at all till now; I have not added any oil to the engine or frame so the oil level is the same, any ideas? I took the oil pipe off and re-routed it back to where it's supposed to be. Thanks.

I did a similar re-route of the breather line, and also had a similar oil-blow into the airbox. This was during a hare scrambles where I was running up ski slopes completely WFO. I have never run my 450 that hard, so that could have started it.

Shortly after that , if not at that moment, I blew out the decompression plug on the head just above the header. I started to get something dripping on the header. :banghead:

I thought it was a radiator leak, but it was the de-comp plug.

I would double check that de-comp plug before you find out the hard way. I was running a good syth oil when mine let go. There appears to be no damage to the head.

Alot of us have tee'd off the hose to the airbox and left the original hose in place to drain as intended. May not be a good idea to route the original straight to the airbox.

euro models, as mine, have original setup routed to the airbox

I did get oil blown out to the airbox and it was made by two seperate problems:

-oil level too high, constant minor oiling

-defect head gasket, severly pumping oil to the a.box

of course this wasnt happening at the same time

Many thanks! Got a good direction on what to do/fix.

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