Overtaching

[Larry (Bo) Bolander]

I finally got my boat on the water last week. Everything went fine except the Tach was reading about 2000 RPM's too high. It's a 1994 TF170 with a 75 HP Mercury. The motor wasn't overreving, the tach was way off. any suggestions?

 

[AirForce]

Look at the back of the tach and see if its set correctly. Was anything changed as far as the tach is concerned? Has it read correctly before? If its still set to 6P, then move it a couple of settings and put it back to 6P - just be careful not to take it past any settings outside its limits. Sometimes just moving the setting will correct itself. IF that doesn't do it, start looking at the stator and all connections to the switchbox to make sure no connections appear burnt, etc.

 

[Larry (Bo) Bolander]

Look at the back of the tach and see if its set correctly. Was anything changed as far as the tach is concerned? Has it read correctly before? If its still set to 6P, then move it a couple of settings and put it back to 6P - just be careful not to take it past any settings outside its limits. Sometimes just moving the setting will correct itself. IF that doesn't do it, start looking at the stator and all connections to the switchbox to make sure no connections appear burnt, etc.

It read correctly last year, last time I had it out. I recently had some alarm issues where I changed out the impeller, thermostat, oil sensor, oil tank and warning module. I never touched anything under the dash.
By the way, I appreciate your help. Thanks, Bo.