Which counter weight??
 

I'm in the process of piecing together an '82 GS. Just need a clutch to get it moving. I have a friend who will give me a clutch, Pressure Plate, Flywheel, and counter weight from an '89 NA. I know I need to use the bigger FW to accomodate the larger clutch, but should I use his counter weight? I also have an '85 GS, since this one also has the bigger FW but it's on a 12a, would using it's counter weight be the best option?

Thanks,
Joe

The counter weight needs to be matched to the rotors as they are balanced as a complete assembly with the front counterweight and the flywheel and eccentric shaft. A factory flywheel is balanced with the assy so it functions as both the flywheel and the counter weight. An aftermarket flywheel uses an automatic counter weight and the flywheel is like a normal boingers. the 85 12a had heavier rotors so it will not work and the 89 13b is right out. You will need an aftermarket flywheel to use the large 225mm clutch assy on an 82 or earlier 12a.

Hope this helps:D