Crank seal on '89 KX250?

[keithluneau]

Quick question...

I'm almost sure my crank seal is leaking on the clutch side on my '89 KX250. Tranny oil is disappearing, no leaks anywhere, and it's smoking alot, and smoking all the time... Plugs come out oily, and sometimes foul.

So, my question is, is it possible to change at least the right side seal without splitting the case? I've got some new seals in a seal kit I bought for other ones, and would like to throw one on there to keep riding for the summer, then do a complete rebuild this winter.

I'm pretty sure I remember the left side behind the flywheel has a lip on it so the seal can't come out that way. I've never laid eyes on the clutch side seal though.

[pickledkiwi]

You will have to split the cases to change the RHS crank seal.

There may also be a groove worn into the crankshaft where it runs against the seal. If this has happened, you may be able to find a seal that has an oversized sealing lip that will take-up the additional clearance that the groove has created. You don't have to use a Kawasaki seal. There are standard automotive seals that will fit the journal and the crank diameter. The auto seals usually have considerably more options than motorcycle seals - and they're also usually less expensive.

To do the job properly, and to avoid damaging your new seal, you will need some specialist tools or a large socket and a bit of patience.

Seeing as you'll end up with your motor split and at least the RHS bearing removed from the journal, you should also take the opportunity to replace both crank bearings and seals and check the crank main bearing and all the transmission bearings.

Happy splitting!
Peter