‘76 Cam Seals?

[rossness]

hey guys

I have a ‘76 that’s I’m replacing the valve stem seals on as I m losing some oil and have a smoky exhaust on the left side. I was going to replace some of the gaskets (bought from mikes) as well.

In disassembly I found some oil pooling in the points(pamco)/advance covers, as well as a bunch of oil grime under the covers on the block. I figured I should do the gaskets on those housings, but should I do the cam seal as well? Also, where do I find that? Mikes only has one for 80-84.

Thanks in advance!

 

[5twins]

If you found oil inside those housings then it is the seals. The gasket and o-ring on the back of the housings just keeps oil from leaking to the outside of the motor. If you do replace them, don't get them from Mike's, get them from Yamaha .....

https://www.partzilla.com/product/yamaha/93102-25090-00?ref=62d1e0c2d701e33ae846d25fa478f585d31cc7fc

These are the thin seals (5mm thick) that Yamaha used on the 1st 650 models, and has now gone back to using. The cam doesn't stick out from the sides of the motor very much so a thin seal, seated as deep into the housing as possible, is required and works best. Mike's sells 6mm and 7mm thick seals. The 6's may work but the 7's barely work at all.