What is missing?

Okay, I just bought an 04 YZF450, and I have found that there is a plug or something missing on the front/top of the cylinder, just above the headpipe. I am not sure if there is supposed to be a rubber plug, or some kind of oil bypass valve or what. Something is definitely missing, as oil sprays out of it when it is running. I have checked the manual, as well as an online microfiche, but they have no details of it. Anybody know what is supposed to be here, or any alternative to plug it? :applause: I would appreciate any input.


OK, I found out that it is just a spot for an alternative decompression kit. I guess I will just order a plug for it. :applause:

Don't replace it with the same piece of (plastic) that Yamaha stuck in it, which, incidentally is item 15 on the camshaft Chain page of the parts manual, because it will fly out again.

Use one of These Plugs instead.

It's highly probable that there is automotive steel or brass cup plug you could find that would do the job, too, but it would be a little harder to install, and, of course, you'd have to hunt for it.

Also be sure to check that your breather tube is not pinched or blocked. That's the usual cause, but the OEM plug is so flimsy that it will drop out just because it's Saturday.

hahahah nice

my bad

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