Ktm countershaft seal

I have a 2007 ktm 250sx i just got not too long ago, its an amazing bike i love it. First ktm ive owned and so far its great. But ive been having problems with the countershaft seal (behind front sprocket) it leaked when i got it so i put a new one in, i bought the whole kit (seal, o ring, and spacer) put it in & rode once & it leaked heavily not even 10 minutes into my ride so i went & bought the whole kit again & put it in. It help up for a couple rides but at the last race (gp) it started leaking again. Any tips or tricks to stop this from happening again? I put the seal in perfectly so no issues there. Anybody who has experienced this would be a huge help. Thank you!

This is a common issue. The search function is your friend. Some countershaft sprockets are thinners than others, and they don't compress the o-ring as much. Sometimes, seal kits will come with 2 o-rings, standard and thick. Also, KTMTalk has a lot of useful info

The All Balls/Moose/MSR kits all include the thicker oring.

Okay thanks guys!

Make sure you don't have a nick or burr on the countershaft which might be cutting into the o-ring and causing it to leak after a few rides

Make sure your chain is plenty loose!

If it is to tight it pulls on the counter shaft and makes it leak

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