T500 crank seal question

[ro55o]

Hi, I recently rebuilt my engine and copied the crank seal orientation as I found it (spring side towards bearings on both sides) when installing new seals.
Both right and left crank seals have failed.
It was smoking and losing tranny oil so did a leak down test and it was hissing out both sides

I would have thought that the right hand side would have spring facing out as that is where the tranny oil is and thats whats being sealed out of the crank case, but Ive googled and cant find an answer for the T500, so Im sure someone can put me right.
The seals were Suzuki ones so not cheap copies.

If the seals WERE originally correctly fitted (ie springs toward bearing) any ideas to what could cause both new seals to fail within a few months?
I have only removed the right side so far and that came out very easily unlike the previous ones and there is no sign of damage to the lip etc.

Thanks
Ross

[Jimroid]

That sucks. Springs go in towards bearings, so you had that correct. Crank runout will eat up seals. Is the crank true? Does it vibrate horribly?

[old racer]

Did you use genuine suzuki seals.

[ro55o]

Yes suzuki seals.

Not very vibey and crank seemed OK.
Looks like a strip down and Ill check the run out on crank. I have ordered new seals but maybe its a waste of time fitting them.
If all else fails its off to an expert for a crank rebuild..... but thats the way it goes sometimes!!

Thanks for the replies.
Cheers

[Jimroid]

Trust me, if the crank or bearings are junk, you won't be able to keep seals alive. Just for grins, pop the flywheel off and do a quick check of crank run out on the taper. And try wiggling the end of crank too.

[tz375]

And inspect the shaft for scratches and rust spots etc. If the shaft isn't perfect, it will be hard for it to seal and it will eat new seals.

[ro55o]

Thanks for the suggestions guys.
I havent had time to investigate further yet, but Ill do as you suggest.
Ill strip down and give the crank a good inspection and check for problems.
Im expecting its time for a crank rebuild now, so Ill contact Pete O'dell and get it sorted properly.

Cheers

[ro55o]

Ive done a bit more investigating and theres no movement on the crank either side when wiggled.
Run off on crank end taper on left is next to nothing.

Ive been looking closer and spraying soapy water around likely areas, and left seal does not leak but its the join between the crankcase halves in one place.
Right side put the seal back in and I have the same leak on the right from the case join and with a tiny amount of air from the oil seal.

The place that leaks loads is around the primary gear spacer (09180-25012) and the key/key groove.

This seems to be a strange way of expecting it to hold a seal as its metal on metal with a groove in it??
Is this a common problem? Am I missing something?

Im going to have to strip the engine to fix the cases and check the crank more fully but off to the classic TT (not on the T500 as planned!!) so it will have to wait a bit.

Thanks for the help so far.
Cheers
Ross

[sportston]

Its not an uncommon problem on 2-strokes. Especially if they have been rebuilt using the wrong type or insufficient sealant. Not all sealants are petrol and oil resistant. When you rebuild, check there is no damage on either surface and no bits of dirt or old sealant preventing a close fit and good seal.
I learnt this the hard way when I was a boy rebuilding my Dad's MZ with the wrong type of sealant. It ran, but didn't like starting and was impossible to tune properly. I had to undo all my hard work and start again. Its a bummer I know.
Make sure you don't use a silicone based sealant.
Use something like this http://www.intek-uk.com/threebond-1184- ... abond.html" onclick="window.open(this.href);return false;