Main Seal Replacement

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Well, I had hoped that by adding the PVC breather valve that my leaking oil into my otherwise dry belt primary problem would be solved.
Nope.

So, I have replace the mainseal after some 8 years.

Which do I get, with the steel OD or not?
And from what source here in the states do you recommend?
Thanks
 
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I purchased the" yamaha" sx valve for $16 plus shipping and installed it two weeks ago, still leaking into primary.
from mikes xs products

are there advantages and/or disadvantages to what is available nowadays as regards differing mainseals?
 

Chris

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Hi
Replaced my seals a number of time before I found the case was pourous? & I had fitted one of Steve Maneys very expensive seals!
Good luck with yours.
Chris
 
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Chris, I admit to being confused by your reply.
The crankshaft seal is rubber around the crank as it enters the primary, that appears to be what is allowing oil through.
You say your case was porous? How would a porous primary case allow oil from the engine through the seal and into the primary?
 

ILLF8ED

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I had a leaky crankshaft seal for quite a while. Finally cured it the an all rubber type seal from Rabers (San Jose). After that was told the type with metal on the outside should be glued in with locktite or similar. I did notice when removing the metal type seal, it sas loose and rotating in the crankcase, so that was the problem. I also have added the Yamaha reed valve which didn't cure the leak. What I notice now is when draining off the wet sump the oil doesn't come out very well as it doesn't have a way for air to get in - that's a good thing. Means the reed valve is working. :)
 
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thanks for the comments, I am placing an order with old britts for a steel OD mainshaft seal, that's the only kind they have!

I also called Rabers, they only have the steel OD seals, no all rubber
 

ILLF8ED

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highdesert said:
thanks for the comments, I am placing an order with old britts for a steel OD mainshaft seal, that's the only kind they have!

I also called Rabers, they only have the steel OD seals, no all rubber

Talk to Richard at Raber's. I'm a long time customer and they let me go into the parts bins. In that box on the shelf are both metal and rubber type. No matter, I think the metal type will work fine as long as you do what has been suggested - glue it in with locktite around the outside of the seal. :)
 
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The important thing when using Loctite is to make sure that the surfaces are absolutely oil-free. Best to remove drain plug and prop the bike up leaning to the right overnight and then clean with a cotton bud and solvent.

The job is worse on a Mk111 850 as there is no lip behind and the seal can only be positioned squarely by carefully feeding in the silly wire circlip in front of it.

After continued problems with mine spinning, Norman White machined the drive side case to accept a top-hat sleeve which is grooved for circlips on both sides of the seal.
 
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