EVO All Evo Model Discussion

Primary seals replacement

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Old Jan 27, 2022 | 06:53 AM
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Default Primary seals replacement

Found a recurring drip from the front of the inner primary seal. So I guess i’m pulling the primary and replacing the seals. It a ‘99 FXR2. I’ve never done an EVO, but i’ve had my old M8 semi-apart to change clutch and compensator. I expect its pretty similar but just looking for any “gotchas“ to look out for, or general suggestions.
 
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Old Jan 27, 2022 | 07:49 AM
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Remove the battery.
Reverse thread on the main shaft.
Remember to remove the starter jackshaft and the starter from the inner primary cover.
Replace the seal for both the main shaft and the starter jackshaft.
Don't reuse gaskets.
I'd say those are the main things.
Sorry if I went to basic.
 
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Old Jan 27, 2022 | 08:35 AM
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Originally Posted by JensWest
Remove the battery.
Reverse thread on the main shaft.
Remember to remove the starter jackshaft and the starter from the inner primary cover.
Replace the seal for both the main shaft and the starter jackshaft.
Don't reuse gaskets.
I'd say those are the main things.
Sorry if I went to basic.
Cool, I have the service manual as well so I'm sure I can figure it out, just looking for the things that people always know better then how its documented!

Like, stick with HD seals/gaskets, or James, cometic, etc?
 
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Old Jan 27, 2022 | 08:44 AM
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Unlike the newer M8's, the evo uses a large O-ring to seal the front of the inner primary to the engine in the area your describing (where it's leaking in the front).

Not saying it's your source for the leak, but you need to be careful with the new O-ring when installing the inner primary. Not easy to do but can be nicked.

Also look at any thru bolt holes. I had one of those leak and all I needed was to remove old sealer, clean and apply new silicone. Did not have to pull primary to seal it up.
 
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Old Jan 27, 2022 | 09:12 AM
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Originally Posted by Yankee Dog
Unlike the newer M8's, the evo uses a large O-ring to seal the front of the inner primary to the engine in the area your describing (where it's leaking in the front).

Not saying it's your source for the leak, but you need to be careful with the new O-ring when installing the inner primary. Not easy to do but can be nicked.

Also look at any thru bolt holes. I had one of those leak and all I needed was to remove old sealer, clean and apply new silicone. Did not have to pull primary to seal it up.
I wasn't aware this existed. So there are no real seals there, you just goop up the bolts with permatex? That's how they are built?
 
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Old Jan 27, 2022 | 10:45 AM
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From the factory, the chain tensioner bolts (2 of them) are sealed with silicone from the backside of the primary, after the bolts are installed. It's just a gob of silicone put over the holes. You can actually see the bolt threads as the hole are a complete pass thru.

The gob of silicone stops that bolt from weeping primary oil.

I am at work right now, but I can post pics of what I mentioned this eve. It's an easy thing to do, but needs to be done. Some of the later model castings of inner primary have those bolt holes closed.
 
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Old Jan 27, 2022 | 10:59 AM
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Bolt # 6 is 10-32 X 5.25" So you always worry about breaking it
Use your favorite thread locker

 
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Old Jan 27, 2022 | 01:25 PM
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Double check that leak is not from the stator plug.
 
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Old Jan 27, 2022 | 01:36 PM
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Originally Posted by Mchad
Found a recurring drip from the front of the inner primary seal.
Perhaps you could clarify where you find the oil.
 
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Old Jan 27, 2022 | 01:55 PM
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Originally Posted by JensWest
Perhaps you could clarify where you find the oil.
Under the front inner primary seal. Removed the "of the" - So the big o-ring between the inner primary cover and the motor. Where the stator is. Clear?
 
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