Two Stroke Motocross

Two Stroke Motocross Forum => General Two Stroke Talk => Topic started by: goodwood on July 12, 2011, 06:08:47 PM

Title: Tranny oil getting in the piston
Post by: goodwood on July 12, 2011, 06:08:47 PM
Help, I think tranny oil is getting in the piston, causing excessive smoke and no power.

What is causing this?  A crank seal?  Which one?  How to replace?

Thanks for you help....it's been a bitch having to ride my 4 stroke  >:(
Title: Re: Tranny oil getting in the piston
Post by: goodwood on July 12, 2011, 06:46:44 PM
Could be coolant also, any ideas?
Title: Re: Tranny oil getting in the piston
Post by: scotty dog on July 12, 2011, 08:44:38 PM
Sounds to me like a crank seal, it really the
only way for oil to get in there,
It would be the
right one but depends if you have to split the cases
What sort of bike is it?

Title: Re: Tranny oil getting in the piston
Post by: Coop on July 13, 2011, 05:46:58 AM
Is your oil level going down? Is your coolant level going down? The answer to those questions we will help make further diagnosis.
Title: Re: Tranny oil getting in the piston
Post by: SachsGS on July 13, 2011, 08:17:24 AM
I've learned over the years to start with the most obvious first and work your way along from there.Have you checked your carb to make sure the bike is not simply running too rich?Left a rag in the air box?(Been there,done that). A leaky trans. side crank seal will have less of an effect on power then,say, a worn needle and seat assembly in your carb. ;D

If your crank seal is leaking grab the flywheel and see if you can detect any play there,crank seals usually start to leak for a reason.  
Title: Re: Tranny oil getting in the piston
Post by: xandyx on July 13, 2011, 12:47:46 PM
Help, I think tranny oil is getting in the piston, causing excessive smoke and no power.

What is causing this?  A crank seal?  Which one?  How to replace?

Thanks for you help....it's been a bitch having to ride my 4 stroke  >:(

sell the thumper and buy a new set of crank seals, and you get 2 problems solved!