Ok well story goes, I just rebuilt my motor using 86-88 rotors, ALL new apex seals, O rings, all new gaskets.. Everything new cept for housings rotors are used, but perfect condition..

Well I messed up Oil control rings, and I guess I fried them... First rebuild was burning oil cuz an o ring was in upside down (don't ask, I feel stupid enough already hehe) Well I opened it again and fixed it and it was fine until now it burns oil.. and I need to rebuild again..

Well do you guys think if I bought some used 89-91 rotors, I could use my apex and side seals and whatnot without having a compression problem ? I would draw where the seals are now on the rotors, and put them in the relative same spot on the new rotors.. But do you think I'd be fine doing that?

Also, If I bought the new rotors, All I would need would be the corresponding flywheel and back counterweight Correct? Thank you..

 

Unless your current rotors are burned or galled where the oil control ring seats they should be good to go for another try.

The critical thing here is to make sure you install the oil ring springs correctly. They are directional, and there are two types. One is for the front of either rotor and the other pair are for the rear.

You can reuse the apex, side seals corner seals, and associated springs you are currently running. I would install new oil seal o rings and the combustion and coolant o rings.

But to answer your question, different rotors use different front and rear counterweights. You need to ask someone more knowledgable than me how you go about determining which weights to use if you are not certain the weights you have go with the rotors you have.