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!!

how old is the boat?? things could be corroded and would just need cleaning.. on snowmobiles when tacs do that they are going bad

Check behind the tachometer. Check the wire connections and tighten any loose nuts. These connections can loosen up over time and cause the tach to read erroneously. It's not the only cause, but it's something that you can do yourself to save yourself a couple of bucks.

Good Luck!

The boat and motor are both 2003. The motor is a Yamaha 4-stroke. I will clean all the conections and see what happens. Thank you for the comments.

Go ahead and try all that first, but I'd be willing to bet the tach is bad. That would be funny if it popped out like a cartoon, I just pictured that! BOINGGGGGG!!!!