I had my non-functional tach repaired by a well known instrument repair business. The circuit board was replaced. The first time I fired up the motor the tach worked but the needle stuck at about 2200 rpm as the needle was travleling back to idle. I was able to unstick it by running the motor up to about 3000 rpm. Is this a fluke or a problem?

HAd the same problem with my 70. Needle would stick and then after revving the engine it would go back down. Now after running it 10-15 times the needle is now free and returns on it's own

ALbert

I had the same problem. I was told a small metal filing left behind from the rebuild causes the sticking. Problem may fix itself if the filing moves -- otherwise you would need to remove and clean the tach’s insides.