I purchased this tach a year ago without any problems to date. Yesterday while leaving Salisbury NC and heady about eighty miles to my house it quit near Gastonia NC. When I got home I shut of the bike and turned the key back on and the tack did not cycle like it should but the needle droped lower than 0. Today I put the key in and it went up to 8,000 and back to 0 like it should, so I started it and went for a little test run. After two miles it went back to 0. I stopped and fueled up and it is working fine again and has not acted up. I originally thoght something is loose but before I tear into it I was hoping someone else has some input. The tach may be bad also.