leaky new crank seal

[zataomm]

I have a 65 cb77 with 305cc motor... i recently had ed moore redo my transmission along with a new clutch basket all that. While I had the motor out and apart, he wisely guided me to change the oil seals.

I'm kinda new into this, if you cant tell already.. anyway, got everything together fine and running again, however, now I have a significant oil leak (one good drip every 10 sec or so at idle speed). It's coming from the right side directly below the crank. I took the stator rotor off and the gear that the starter engages to find the crank oil seal was not flat anymore. The seal is now more concave, the outside edge is fine and flush with the case, but the center is pushing into case (slightly less than 1/8").

Could this be causing the leak??
If so, is it possible to replace this seal with the motor cases together???
And most importantly, what caused this concave-ishness???

It looks as though the leak is coming from the center of the seal. I am pretty sure i installed the seal correctly when i had the cases apart and with no gasket material around the seal itself. And I am also pretty sure i installed the starter gear and stator rotor correctly, but is it possible for this assembly to be tightened too much as to put pressure on the seal and push the center of it inward? I was told to tighten the bolt holding the rotor as tight as possible. And yes, the woodruff key is present and accounted for.

Any ideas? I've come so far on this project and it's such a ball kick to be held back by a oil leak.

Thanks for the help
Ryan
(I'll try to post some pics soon)

[Dgormley]

Ryan, check the crankshaft to see if it's grooved where the seal goes. I use a small amount of sealer on the outside of the seal and make sure it seats completely and squarely

[zataomm]

Thanks for you response.

What type of sealant do you recommend?

And is it possible to remove and re-install the crank shaft oil seal without taking the cases apart.. leaving the motor intact and on the bike???

Thanks again,
ryan

[gramey7]

Yes you can replace the seal without splitting the cases. I rebuilt my engine a couple of years ago and although I installed new seals, the crank seal must have been an original 40 year old seal and was hard. It leaked. Bought a new seal and noticed it was much more compliant than the one I used in the rebuild. I may have used Hondabond around the OD when I replaced it, don't remember, but it no longer leaks. I had a piece of pipe the same OD as the seal and gently tapped it in.

[zataomm]

Thanks very much for your responses...

I figured out what the problem was this morning. After re-examining everything on the third disassembly, I discovered I was using the cl77 oil seal instead of the correct cb77 seal. It's crazy it was even possible for me to bolt it up this way.


Everything is back together and running fine, leak-free!