Tachometer not working correctly

[snosptz 0]

I have a 2000 Monterery 262 Cr with 5.7 Mercruser. I just recently reconized that the tach was over revving. The more I watched and listened I relized that the tach showed that it was over revving BUT the engine was not really over revving therefore it appears that it is a problem with the tach and NOT the motor. My 1st thought is that it may be a ground wire. Do I look under the dash 1st at the wiring or is there a connection to the motor. My major question here is where do I look on the motor for the connection???? I also relize that it could be a bad tachometer. Any help is appreciated.

[Dan 0]

I have a 2000 Monterery 262 Cr with 5.7 Mercruser. I just recently reconized that the tach was over revving. The more I watched and listened I relized that the tach showed that it was over revving BUT the engine was not really over revving therefore it appears that it is a problem with the tach and NOT the motor. My 1st thought is that it may be a ground wire. Do I look under the dash 1st at the wiring or is there a connection to the motor. My major question here is where do I look on the motor for the connection???? I also relize that it could be a bad tachometer. Any help is appreciated.

I have the same problem with both of my tach's but it's very sporatic. I just tap on them then they go down to the correct reading. I have heard of folks stating that issues with grounds...I have not done any trouble shooting on mine but MOST has mentioned before that there is a lifetime warrenty on them...Maybe they'll chime in.

Dan.

[RSUMRTOY2 0]

I have the same problem with my Starboard 5.0 Mercrusier Bravo 3...The Port is 4,000 the Starboard is 5,200...I tap the Starboard and it goes back to 4,000. I checked ground on the back of the tach...O.K. I will remove the tach next month when the boat comes out of the water and send it to Faria for calibration/repair.