A friend of mine is having some trouble with his mach 1. I have been told it could be the inner seals or the rotary valve. What are your thoughts?
The sled runs great but will drain the oil tank into the case then its a bitch to start. How tough is it to pull the motor and fix the problem??

Thanks

Sounds like rotary seals to me, not too hard to do, get a servive manual for the sled, many libraries have them, perhaps "Sam's Photo Facts".

Don