motor has a major vibaration
 

i have a 93 rew motor and used a 20B automatic counter weight with a os giken twin disc clutch and now i have a major vibration in the motor do you thinks its the counter weight or is it in the motor itself. does any one know if the 13b weight is the same as the 20B one

well, I believe the front CW counters the middle and rear rotors...as if they were one, so I don't know if the rear 20B CW can be similar to a 13B due the the distance (and phase) to (of) the front rotor? I could be totally off here...but why did you chose that CW???
https://www.rx7club.com/attachment.p...hmentid=127118

its all i had when i was building the motor and i know so many guys use the 93 flywheel on the 20b and have no problem

thats becaus the counterweight is the same for that engine, but I think the counterweight is different for the rew, not sure though. the flywheel doesn't make the difference in vibrations, the counterweight does


dpf22

If you're going to mismatch parts you need to have the assembly balanced. Since you have the motor together and you're on a budget, find a S6 auto cw and hopefully it will be within the wide factory balance range....