105SX pushing out left crank seal... What gives?

[Dirty Dave]

My son just bought what was advertised as a primo '06 105SX and paid good money. At sellers house bike started and ran cleanly. At the first op we took the bike out to friends orchard to let grandson get the feel of the 'new-to-him' ride. After about 10 minutes of moderate riding the bike died... on the far side of the field naturally. After much kicking and kind words my son finally got it going and headed back towards the truck but with a huge smoke screen following him back. Long story short... found left crank seal sleeve missing, crank seal pushed out against the crank gear, and crank case full of trans oil. Installed new sleeve and seal. Bike started first kick, idled/rev'd cleanly for about 5 minutes then began to completely blanket neighborhood with thick white smoke. Opened it up again and once again found seal pushed out and crank case full of trans oil. :yell: Help!!!!! :bang:

 

[whenfoxforks-ruled]

For some reason the bottom end pressure is getting too high? Or, the bore that holds what is pushing out is wore too much? Not familiar specifically with a 105sx, ktm? Vintage Bob

 

[Dirty Dave]

For some reason the bottom end pressure is getting too high? Or, the bore that holds what is pushing out is wore too much? Not familiar specifically with a 105sx, ktm? Vintage Bob

Sorry... Yes it is an '06 KTM 105SX :nod:

 

[Dirty Dave]

If the exhaust valve (I'm not sure what KTM calls it) was stuck closed would it cause this when rev'd?

 

[whenfoxforks-ruled]

Closed it would seem to alter crank case pressure at wide open, imo that is. Typically that is a vacuum draw, and very low pressure. Does the engine vibrate at higher rpm, worse? Crank alignment/balance?

 

[Patman]

Installing the seal with some locktite may help.

 

[ellandoh]

mine came out once in a lifetime......the day i borrowed fuel from my cousin. lots of spark knock and such, possibly a coincidence , just my experience though. pushed it back in at camp went to town got my own fuel, its been there since, going on 2 years so far. maybe next time ill change it. :ride:

 

[2strokerfun]

If it happened twice now, I'd probably disassemble the engine and check bearings and crank (and crankcase, too). Strange.

 

[whenfoxforks-ruled]

I have seen a center punch mark or 2 properly placed, close enough to the edge to roll a little aluminum over to stop it. Is there a particular brand of seal being used?

 

[mideastrider]

How easy does the seal install? Just push it in with your fingers or no way and having to use a knocker. If its going easy just clean the bore and seal with something like brake clean and install using an adhesive and you should be fine. You do realize being a KTM your supposed to take it back to the dealer. They are the only ones in the world that are authorized and capable of making the repair. That's straight from the dealers mouth.

 

[Dirty Dave]

Thanks for all the suggestions and sorry it took so long to get back here. The seal is KTM. I will tell my son to check the exhaust valve operation and to clean and secure the seal into position when he gets time to tear it down again. Thanks again.