I finally got my 1200 running again after fixing a problem with the oil sling washer behind the harmonic balancer. I had noticed that when I tightened the large front bolt on the balancer there would be quite a bit more runout compared to when it was left slightly loose. I took the front cover off, and found the sling wahser was battered and not allowing the balancer to seat properly.
Now that that is fixed the vibration has only lessened, not gone away. It does it at high RPM in any gear, regardless of MPH.

Could the balancer be bad? I doubt the engine is out of balance, but my flywheel may be- I had it lightened while the engine was out. No balancing was done, since I've gotten away without it before.

What would you do in thsi situation? I just want this thing to run right, I'm tired of fussing with it.

hmmm balancer? Do we even have those?

Presumably the flywheel was balanced when lightened...

Vibration like what?

what rpm?

lol tired of fussing he says... it takes a lot of work to have a 30 year old car that you won't need to fuss over.
Even when it all works perfectly, things mysteriously fail.

Check out your uni joints and the driveshaft balance too. Especially if it happens at the same revs no matter what gear you are in and is not present when free revving the engine.

The flywheel wasn't lightened because Iit was machined by my father. He didn't balance it.

I'm tired of fussing because I own two other 30 year old cars, work a full time job and raise a five year old on my own. I've been working on cars for years, but I don't really have the time for this sort of thing that I used to.

If i could determine exactly why its vibrating that would be great. i think the snout of the crank may be bent as well. i remember there being some runout with the pulley off.

I have the option of putting in a free a14 or fixing the A12. The A12 would be legal for SCCA auto-x in F Street prepared. The A14 would put me in a street mod where it wouldn't be competitive. I guess I could just enjoy the A14 on the street.

If the A12 needs a new crank it may not be worth fixing. The cranks don't seem readily available in the US. Maybe I'm wrong.