Oil Leaking onto header pipe

I thought I had a rad leak but it turns out it is oil. It is coming from the cylinder as per the picture [image]http://www.imagedump.com/index.cgi?pick=get&tp=81457[/image]. Oil is coming out of here. Being blown through the rad and dripping on the header pipe. Then the oil burns and smokes like crazy. Any ideas what is going on? Any help would be greatly appreciated.

Thanking you in advance,

C'mon gentleman.

Someone's got to have some ideas. Don't leave a brother hanging. I'm getting smoked out here.

Bumpin it back up. Any ideas on what is going on?

You say its leaking oil from the cylinder onto the header pipe? If so have u check the plug right above ur header pipe on the cylinder to see if it has blown out? Then if thats not the case then maybe gasketleak? Or bolts not tightened down maybe vibration caused them to loosen up.

You say its leaking oil from the cylinder onto the header pipe? If so have u check the plug right above ur header pipe on the cylinder to see if it has blown out?

Looking at the picture, this has to be it. It's on the head, btw, not the cylinder.

It's the plug covering the manual decompression mechanism where the lever would go in. Yamaha part number 90338-18064-00, will cost you about 2 bucks.

I've got one on order. Thanks for the reply's. Could I have done any damage with the plug missing?

common problem, i know a few guys who lock wire the plug in. :thumbsup:

Could I have done any damage with the plug missing?

Not likely. I guess you could lose enough oil to do some damage or take in some crap through the hole but that's stretching it.

I'm blowing oil onto my header as well. I've had the radiators tested as well. I was at the dealer today and they thought that Yamaha recently broadcasted a notice addressing it.... but he couldn't find it.

Has the $2.00 part corrected the problem for you?

Iyou are running the auto decompression cam, buy the aluminum plug made here by a TT member. It comes with the seal and uses the bolt to hold it in, whereas Yamaha's solution is press fit and will blow out with crankcase pressure. If you are running the compression release forget all I said.

Thanks. I ride an 03 YZ450F. It doesn't have the decompression lever. I purchased the stock plug last night and put it in. I haven't had a chance to test it out yet. But, it doesn't fit very snug... just slipped right in. Who sells the aluminum plug? I'd like to buy one for a back-up.

TT store.

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