Went riding this weekend and oil was coming out the breather tube and running down over the engine, I realize this could happen if there was too much oil in the crankcase, but thats not the problem.. Is there a pcv valve or anything?

 

was the oil coming from the rear end vent tube, this happened on my wolverine, i finally re-routed my vent tubes to under the handle bars.

 

Grizzjeeper,
I had the same thing happen to me last weekend. The breather tube the oil was coming fron was from the front differential. It comes out right over the exhaust pipe on the right side of the engine. It has never done that before, but one thing different was that last weekend I put'er on its side. I figured some diff lube got in the tube and slowly worked its way out. It happened right before I loaded it up and left. It got my attention because I could smell the oil burning on the exhaust pipe the next time I went out riding. Apparently it is all out now, because I haven't smelled or seen any oil since.

Rick

 

Hey, same thing just started happening with my Grizz after I got it back from the dealers first service! Went riding and I could smell burning gear lube. It was not oil, it smelled different. When I took off the seat I noticed the shield for the exhaust next to the airbox had oil on it, and right below that I noticed a small puddle of oil of some kind on the engine. I don't know if they flipped it on its side when they serviced it or spilled lube everywhere, or maybe just overfilled but I won't rest easy till that smell is gone. Probably take it to the pressure washer.

 

Its probably your gear oil. Since you tipped it it probably figured its way throught the vent tube. And most of the time the dealer overfills all fluids, and when you get to much in your differential, it builds up enough pressure to shoot it out the vent tube. My big bear does the same thing when it overfull. Dont worry about it. It shouldnt be a big problem.

1998 Big Bear 4x4
1999 Grizzly
http://www.bigbadbears.gotoo.com

 

Were you riding at fast speeds? I have had the same thing happen on my (recently sold 92) big bear and only when I ran fast for about 3 miles or more. Thought maybe the vent tube developed a vaccuun that siphoned the gear lube out from the differential from the more violent splashing at high speeds. I know this might sound weird but it's the only thing I could think of and my dealer mechanic said it was possible, as at slow speeds I never have a problem and my machine has never been on its side.

 

i had the same problem too on my 2000 grizz. my tech guy told me its beacuse the gear oil (crappy yamalube) foams up when it mixes with air and comes out the breather tube under the airbox and onto the exhaust. the solution is to drain the front and rear gear oil and use mobil 1 synthetic gear oil... make sure its a hypoid gear oil 80 weight i believe.. it has nothing to do with tipping the bike or any none sense like that... its just crappy yamalube product

 

Hey Grizzzzzzz,
That sounds like it makes sense to me. The one difference is that I drained my front diff when I added the limited slip friction modifier, and refilled it with Valvoline 80w90. That was about 150 miles ago, and I have almost 600 on the bike. That was the first time that it ever "breathed" any lube out of the vent tube, and the only difference was that it was also the first time I had ever put it on its side. So I figured that had something to do with it. At any rate I'm not too concerned about it.

Rick

 

Yea my big bear does it when its ridden real hard and revved up real high(like in high gear)Ive replaced both diffs with new oil(not yamaha stuff) but it still does it. It does really bother me except the smell. And I always have plenty in my diff.

 

thanks guys for the help!!!
it was the front diff, going to get rid of that yamalube crap