Hey guys, I have helped a lot of people on this site, but hopefully this time, I can get some help.
Here is the problem: One day my (factory) tach started twitching and then it just stopped. I honestly don't know where to begin troubleshooting. If anyone could help me that would be GREATLY appreciated. Thanks,
Jed Booth LCpl. USMC

 

The most common problem is a broken cable. From what you have described it seems that this is the problem. Disconnect the cabe from either the engine or the back of the tach and see if you can spin it. If so then replace the cable.

JC