Crankshaft end seal leak on 1100 Kat

[John Kat]

I noticed that oil was leaking out of the right hand side of my crankcase on my 1100 Kat.
I expect it comes from the crankshaft end seal
Could the issue come from too much blow by through the cylinders?
I noticed that the engine spins very easily on the starter and I suspect that the rings are not seated correctly?
This is probably due to the fact that the engine had not been running for at least 5 maybe 10 years?
Wrt to the end seal can it be replaced without opening the cases or is this hopefull thinking?

[rapidray]

The seal can be replaced without splitting the cases, BUT, splitting the cases IS the best way to change the seal. Ray.

[John Kat]

Thanks Ray!
I'll probably do a leak down test first to determine what needs to be done on the cylinders and pistons.
If there's no problem there, I'll try the quick and dirty seal exchange.
If the engine must be opened, then I'll do the proper job.

[chef1366]

Freeze the seal and warm the seal pocket a little.
Grease the seal and use a large socket and tap it in.

[bwringer]

Pay attention to the rotation arrow on the new seal.

It looks like it's backwards when you install it. If you install it what looks like the "right" way around, it will leak.

Guess how I learned this... go on, guess.


You can push the new seal in with a couple of washers, a nut, a large socket, and a long 8mm bolt. Much easier and less likely to cause problems than trying to drive it into place with a hammer.

[chef1366]

You can push the new seal in with a couple of washers, a nut, a large socket, and a long 8mm bolt. Much easier and less likely to cause problems than trying to drive it into place with a hammer.

This is a great idea! I did it this way the last time and the seal didn't keep going cockeyed with the tapping method.