Some people should not be allowed to touch anything mechanical

[SteveW]

Just took the sprocket cover and sprocket off the 650 to investigate a slight oil leak and found this:

I've cleaned it all up and waiting for the leak to appear, I'm hoping its the gear selector shaft seal.

 

[Nurse Julie]

😭😭😭😭😭

[McCabe-Thiele (Ted)]

Presumably someone prised out the old seal chipping the edge instead of using the screw method?

[SteveW]

I think the seal on the 650’s has a shoulder on it so the only way to replace is to split the cases.

[SteveW]

Just bloody great, its leaking where the sprocket shaft goes through the seal 

[McCabe-Thiele (Ted)]

I wonder if all the marks are where a replacement seal has been forced in or is it previous chain damage?

[Oddjob]

There is supposed to be an oring behind the bearing and between the gear positioned there. It's there to stop oil weeping along the shaft, under the collar (which is what the seal seats on) and then coming out along the shaft again. It's either failed, perished or is missing.

[SteveW]

Can’t see an o ring.

[SteveW]

Looking on the cmsl website the oil seal does not have a shoulder like the original.
So in theory, if I can get the old one out I won’t have to split the case.

[Oddjob]

Sorry Steve, the 500/550 have the oring so I'd have expected the 650, which is essentially the same engine, would have one too.