View Full Version : Tach off by 4000 RPM

09-11-2006, 05:56 PM
I was driving my neighbor's tristar for him on a tricking run last weekend and noticed that his Tach was way off, idle was at 4000 RPM. When he bought this boat the mechanic at the marina he bought it at said that they were all like that. I know, let's not flame whoever this hillbilly is.

What can be done to adjust the tach to read the proper RPMs? Makes it hard to figure out speed/RPMs if you have to add by 4000.

09-11-2006, 08:14 PM
You don't mention the year but if its a TriStar I'll guess early 90's. If the boat has a point ignition system, the tach leads should be connected to the distributor side of the coil and ground. Also, is it the original tach? I've seen some aftermarket units that have a setting for 4,6 or 8 cylinder modes......an incorrect setting would throw it off.

09-11-2006, 08:34 PM
You can always impress wally's that you slalom ski at 7000 rpm!

09-11-2006, 09:19 PM
You can always impress wally's that you slalom ski at 7000 rpm!

Or Trick at 6000. :headbang:

It is an 89 like mine except with an open bow. He just had the breakerless ignition put in and it has the original tach.

He has pulled his boat out, as they are pulling the lake as of Labor Day and it was down 5 1/2 feet then so there is no telling how far they have pulled it already. No more getting to the slalom course for me. :mad:

09-11-2006, 11:10 PM
Verify, like LLS said, that the tach is properly wired to the coil. IIRC the purple wires should be attached to the + positive, side of the coil and the black wire to the - negative side of the coil.