Oil leak, camshaft seal, cover gasket (or both)?

[queenslegs]

After a good 200km run yesterday I noticed some oil spray along my right side cover.

Head gasket looks good, top bolts look good so I figure its either the camshaft seal or cover gasket/o ring, or both. There is a bit of oil inside the cover but I would have thought it would be messier in there if the seal was leaking. Ideas? I'll pull that advance mechanism out and have a look. Not sure if I should order the seals or not. Thanks.

 

[fredintoon]

Hi QL,
FWIW, oil can only get into the mechanical advancer cover if it's leaking past the camshaft oil seal.

 

[5twins]

Yes, it's got to be the seal. The gasket and o-ring behind the housing seal the outside of the housing against the motor. Before resorting to seal replacement, there are a couple things you can check/try. Make sure the seal is pressed in and inset as deep as it will go without hanging out the back of the housing. It has to be inset deep for the seal lip to get on the cam. You can also do a good cleaning of the end of the cam shaft where the seal lip rides. Buff it clean and shiny with a Scrotchbrite pad. Many times this will cure a minor leak.

If it does come down to seal replacement, the new "improved" triple lip seal from Mike's is not recommended. An original single lip type right from Yamaha will work better. Which begs the question - what is in there now? Did you already replace it with that "improved" seal or is it an original?

 

[queenslegs]

Thanks Fred and 5T, it was one of those questions where I kinda knew but was hoping for a different answer lol. Ordered the seals from my local Yamaha dealer. (boats.net shipping to Canada is a killer) I'll try your suggestions 5T. The seal that's in there now I replaced winter of 2014/15 with a seal from 650 central; #KCEN93-90291. I'll pull the cover off and post more pics. Every picture tells a story don't it?

 

[5twins]

I don't know which seal 650Central sells but some of their stuff is the same as Mike's. The factory ones are cheaper anyway, and better too.

 

[queenslegs]

Here are more photos...

If anywhere it looks a little oily here... gravity I guess.

Seal is flush with housing.

I'm assuming this surface should be polished.
Thanks again all.

 

[TwoManyXS1Bs]

I can't make out the seal's sizing numbers.
Also, looks like the seal's outer lip isn't riding the shaft properly (unless that's an optical illusion).

More seal trivia:

http://www.xs650.com/threads/need-new-cam-shaft-seal-oring-gasket.36404/

 

[retiredgentleman]

Here is what I know about camshaft oil seals:
From Yamaha parts diagrams; 1970 to 1973 lists #93102-25090 , they are ARS made in Japan, 25mm X 40mm X 5mm wide
1974 to 1983 lists #93101-25044, they are ARS made in Japan, 25mm X 40mm X 6mm wide
Both of these should work fine.They are single lip.
Whatever you do, don't buy the Mikesxs part # 01-9020, the so called "Special triple lip oil seals" , they're special all right, a special piece of garbage! They are 25mm X 40mm X 7 mm wide. They are too wide for the space available, and they leaked on my bike after only 1 season of use.

I'm presently using # 93101-25044-00 that I bought from Boats.net.Only have one season of use so far and working perfect.

The ones from 650central are likely the same as Mikesxs, which means they are junk. You got 2 seasons, and I only got 1 season.