Tranny oil in crank housing... Two stroke

[Kylediffley]

Hey guys I just buttoned up a Ktm 150sx new crank. Started first kick. Then it started smoking like

Crazy! Idk what happened but I mixxed new oil 40:1 and it's still

Happeneing so I figured I'd take a look at crank through the reed hole since the hole isn't on the cylinder but straight to the crank. Put finger in and it's yellowy oil. My two stroke oil is blue so I know it's not two stroke... Any suggestions cause I'm rather worried about the labor I may be doing

[Beau 88]

Hey guys I just buttoned up a Ktm 150sx new crank. Started first kick. Then it started smoking like

Crazy! Idk what happened but I mixxed new oil 40:1 and it's still

Happeneing so I figured I'd take a look at crank through the reed hole since the hole isn't on the cylinder but straight to the crank. Put finger in and it's yellowy oil. My two stroke oil is blue so I know it's not two stroke... Any suggestions cause I'm rather worried about the labor I may be doing

What did you use for assembly , I used competition cams assembly lube building my cr250 smoked like a train for about the first 2 heat cycles . After i got the engine broke in i pulled the whole exhaust and washed it out and cleaned and repacked the silencer. 

[johnnyboy]

Either the clutch side oil seal or the center case gasket were not fitted correctly.

[Kylediffley]

They were both fitted correctly. Is the ONLY WAY this could happen...

[Still Bill]

Drain the tranny and fill with ATF (red).  If color changes, then you can be sure.

[ridleyredraider]

If you're sure it's not one of those, check you don't have hairline cracks in the right case. Had that happen to a YZ250 and was a PITA finally figuring it out.

[Kylediffley]

What did you use for assembly , I used competition cams assembly lube building my cr250 smoked like a train for about the first 2 heat cycles . After i got the engine broke in i pulled the whole exhaust and washed it out and cleaned and repacked the silencer.

Lube for what

[Beau 88]

Lube for what

Everything you would normally put oil on , cylinder wall , piston, rod bearings, in between the tranny gears , all the washers against the cases , shift drum bearings it dissolves after awhile just gives a little added protection better than oil at first start up. 

[Kylediffley]

Yeah I do all that with two stroke lube on crank area and tranny lube on tranny area. But this is serious oil. Like I could taste the oil on my lips from the smoked out garage. And taking pipe off oil spilled out.

[KTM_Pat]

Either the clutch side oil seal or the center case gasket were not fitted correctly.

 

Exactly.

 

Replacing the crank with new seals goes hand and hand. if your crank was originally damaged and the crank breaking were also bad it could oval out the seal. Then the new crank won't seal.

[Beau 88]

Right side crank seal, it may have blown out or if you scratched it up installing it will do that . That's the only passage for trans oil to the crankcase. If you installed the seal dry without grease it probably ate the seal in the first minute of running. 

[SellYour4Stroke]

Probably just muffler fluid. Air the tires up to 90psi and hold it wide open on a trail for a couple hours

 

But srsly. Sounds like a rh crank seal or centercase leak.

[Kylediffley]

I messed up the seal a lil cause I put it in too far and used a flat head to pull it out. Which was my fault. Should I also replace the gasket

[Beau 88]

I messed up the seal a lil cause I put it in too far and used a flat head to pull it out. Which was my fault. Should I also replace the gasket

just that seal should be fine , drill a tiny hole in it, the metal outer ring and screw a wood screw in it , and pull out with pliers . Grease that crankshaft and seal when replacing i just use a big socket the same size as the outside of the seal and tap it around the outside until flush with the case. Seal grease is best i've used axle grease , assembly lube , vaseline as long as it's heavy and last a while until oil gets to it. 

[Beau 88]

I messed up the seal a lil cause I put it in too far and used a flat head to pull it out. Which was my fault. Should I also replace the gasket

Sorry you have had all the mishaps and trouble from that rebuild , but i bet you can do it easily on the next one.  ? It will also make you realise why regular oil changes, running a good premix , proper break-in and regular maintenance is so important . Congrats on the first kick startup , you the man  ?

[kan3]

You should be leak testing your engine after you rebuild it.

[SellYour4Stroke]

You should be leak testing your engine after you rebuild it.

 

 

Totally true. Not many people do, though.  Makes me wanna go out n buy the parts to make one, because its so silly not to.

[AXAxiom]

I messed up the seal a lil cause I put it in too far and used a flat head to pull it out. Which was my fault. Should I also replace the gasket

 

I installed my seal using this method, works great pressing it in even and getting the exact recess

Get the new seal started this way then stack the old seal on top (as Shown is the pick) so you can press the new seal in and be able to recess per service manual

 

Edited June 11, 2014 by AXAxiom

[Kylediffley]

Ok I understand it

[AXAxiom]

Ok I understand it

 

Get the new seal started this way then stack the old seal on top (as Shown is the pick) so you can press the new in and be able to recess per service manual