Vent spewing oil

[Scro]

The vent hose that comes out of the back of the cylinder on my 07 450R is spewing oil. It doesn't do it just idling or easy riding. Seems like it only does it during a race. Any ideas?

[Dave400ex]

That is the tranny overflow. Are you putting to much oil in?

[Scro]

That's what I was thinking at first, but everything's at the right level. Could I be building pressure in the crankcase somehow, causing oil to be pushed out?

[400exrider0004]

mines been doing the exact same thing! I cant figure it out, and it only happens when im riding it hard....

[mrbigzmotoxer]

its normal. when you put them in harsh race conditions they blow offf. thats why a lot of guys put a filter outside their airbox for that hose. it helps if you change ur oil more regulary.

dont worry, its a normal thing

[Scro]

I don't think this is normal. Oil is covering the entire back of the engine and the side. I know several other racers that have their hose routed to the stock position, just as I do, and their's doesn't blow oil.

[mrbigzmotoxer]

is this the hose that goes into the airbox? the crank breather hose? what kind of oil are u using? is it an 04-05?

[IMSROLL450R]

Wait a minute,if its coming out of the back of the cylinder, how is it the tranny overflow?????????? thats just engine oil. Mine does that if its the least bit overfull and run it really hard.

[Scro]

This is an 07. It's defiantely the transmission vent tube coming out of the back of the cylinder; just looked it up in the manual. It goes up to the gas tank shroud.

[IMSROLL450R]

ohhh I see. So you must be running oil in your tranny and not tranny fluid. I was confused. When I got my 06 from the dealer they filled the tranny to the top instead of the check bolt and it spewed fluid out that vent just like you are talking about all over the back of the motor and swinger. Brand new bike.......idiots. Is there a possibility you are just a little overfull?

[Scro]

I'll check it again, but the levels were right before the race. I had a problem with oil swapping, and I thought I fixed it. It may have something to do with that.

When you mix any kind of fluid, be it transmission or motor oil, with black Pennsylvania dirt...it all looks the same:p

[IMSROLL450R]

Originally posted by Scro
I'll check it again, but the levels were right before the race. I had a problem with oil swapping, and I thought I fixed it. It may have something to do with that.

When you mix any kind of fluid, be it transmission or motor oil, with black Pennsylvania dirt...it all looks the same:p

Yeah I know how that goes. My eyes are usually so full of dirt and mud I can't see anyway.........