04 rm250 clutch side seal.

I found oil in my power valve. I need to change the crank seal, but I really don't feel like splitting the cases. An old and very knowledge mechanic once told me if my memory serves that it was difficult to get a proper seal putting the seal on after the crank is in the cases.

Is there a method for doing this and getting a good seal?

Im getting ready to change mine for the first time this Saturday on my 04. Im not splitting the cases and it does not look to be too big of a job. I'll let you know how it goes and if anyone who has already done this please chime in if you know of any tips to make the job go smoother it would be very appreciated.

use plenty of premix oil on the seal and on the case and crank. Then use a seal driver or a socket to set it tight. This is the method that is used in my OEM manual. There should be 2 divets on the case where the seal goes. The seal should be flush with the divets.

Any tips on removing the transmission oil from the crank?

When your talking about the divets mihylo is that just a reference point for how far to put the seal in the opening?

I don't know why this seal failed. I was thinking it was because I put it on without splitting the cases. I had it assembled in the crank when I put a new hot rods crank in but I realized the seal was backwards when I was putting the primary on:bonk:. Took it out and replaced it with a new seal, but it gave out after 20 hours. Cost me a piston too. :foul:

Just run the gear oil out of the motor, it won't hurt anything.
Yep its the indicator for how far to push the seal in. You'll understand once you see it. there are high spots around the hole for the crank and seal then there are 2 divets in the ridge where the seal needs to be seated to.
Did you use an oem seal? The aftermarket seal I used once went after 20-30 hrs. Buy nothing but OEM seals and gaskets, less problems.
How did a bad crank seal cost you a piston?

The seal was oem.

I didn't really take a good look at it when I broke it down because I was pretty mad at the time. I just looked at the black carbon burns on top of the piston and declared it dead. After looking at it again the deposits are not really raised and the burn marks are barely over the edge of the top if at all. The sides have no streaking. The black deposit on the top shouldn't be a problem, right? Maybe just try and clean it with something?

I'm probably just going to order some new rings while I have it apart and a new seal and see how it runs. Thanks for the help.

No scuffing, no problem! You can usually get a good 50+hrs of race time on a Wiseco vs the 20hrs on a OEM. Odd that an OEM seal went bad. Could have very well been done during crank assembly
Good Luck.

i DID NOT EVEN KNOW THIS WAS POSSIBLE TO CHANGE THE CRANK SEAL WITHOUT SPLITTING THE CASE. CAN WE GET A COMPLETE CONFIRMATION ON THIS. THANKS! ALL THE BEST LET US KNOW HOW IT GOES

Sure it is really easy. Just take off the clutch cover then the clutch.

I already had the cylinder off as I was doing some other work. So I just rotated the piston until the skirt was sitting on the bottom part of the cases with a rag under it. Then loosened the primary nut. You can just hold the stator if your overly cautious or don't have the cylinder off.

Taking the seal out was pretty easy. I tapped one end of it until there was enough to grab with needle nose. Then followed mihylo's instructions and put every thing back together.