The Tach on my pontoon is going goofy. It seems to work ok when just idling, but goes crazy with higher rpms. It goes up a little bit then just seems to get stuck there. It also has rotated counter clock wise and came up on the other side. Any one have any ideas?? Is it the tach itself or other problem? I am waiting for the dial to start spinning and pop out with some springs and stuff, like in the cartoons!!