'03 YZ450 leaking oil bad. Help!

Hey guys,

My uncle's '03 YZ450 is leaking oil pretty bad. We are supposed to go on a 3 day baja ride tomorrow so we need to fix this!

We went on a about a 40 mile test ride earlier in the week and here's what was happening.

Oil was dripping from somewhere and the drips were hittting the exhaust and it was smoking. He said he put about 2 quarts in the bike when he changed the oil, so we figured it had too much oil. Drained alittle bit out and kept riding. We stopped about 20 minutes later and it was still doing it, there was quite a bit of oil on the engine.

Not quite sure where it's leaking from, but it's from high enough to be dripping onto the exhaust.

He changed the oil on it today and put the correct amount in it (1.27 quarts with filter replacement) and he said it's still doing it pretty bad.

Any guesses on what it could be? I'm sure this thing had too much oil in it when we went on that ride the other day. He's only had the bike about a month and I don't think it was doing this before.


Decompression plug has fallen out - would be my guess - do a search on this -

TT has replacements for sale

I was going to say the same thing....

It is pretty common.

Or check the oil galley bolt from the oil line going from the case to the head on the exhaust side. It's probaby the decomp plug though. Good luck!

Its the decomp plug, (it happens to most of us) hope you get it sorted in time..

decopress plug. Cost $4 at the dealer..... Make sure the vent hole is free and air is moving in and out of it while it is running....(black hose on left side of down tube.) They get crimped off by the clamp that holds it in place and blocks free flow air and ends up popping out the plug. :banghead:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now