Which Crank Seal to use ?

YamadudeXS650C

Central New York XS650
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Please pardon me for posting a question regarding one of my "other" :rolleyes: bikes, the '74 Kaw F11 250 Enduro, but I'd really appreciate your opinions.

I'm replacing the right hand crank seal.
Just now pulled it :

KawF11Rebuild 002.JPG


......and I have the choice of two replacement seals.

KawF11Rebuild 004.JPG


In a few days I will be receiving a NOS seal just like the one on the left, with a metal outer structural rim. It is typically installed from the inside (cases split) using a press, but I believe it will go in OK from the outside, as I removed it.
On the right is an aftermarket seal, made for this bike. As you can see, it does not have the metal band. However, I imagine that it will go in with more ease. And it hasn't been sitting on a shelf for many years.

Which one would you use?
I'm inclined to use the aftermarket seal.
 
Is that a 2 stroke Jeff? If so, I'd be inclined to use the metal one. Crankcase pressure gets pretty high on a 2 stroke. Metal to metal grip would prolly hold better.
 
I think the aftermarket one is metal, just covered with rubber. The original crank seals I've seen for the 2 strokes I've dealt with were rubber covered like that aftermarket one. Never saw that bare metal type before.
 
Burrpppp.
Turkey.

Yes, 5T, upon examination, you seem to be correct; the aftermarket seal has the sort of rigidity that would suggest that it has a metal outer ring structure at its core.
 
has the sort of rigidity that would suggest that it has a metal outer ring structure at its core.
Just about all Garlock seals are made from a metal ring with rubber molded around them. Whichever seal you decide to use, the main consideration here is making sure it's a tight fit. Crankcase pressures inside a 2 stroke can easily exceed 30 psi.
 
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