Tach keeping boat from accelerating.

dbeall1914

I own a 2008 Rinker Captiva 276. The tach has always wondered up and down quit a bit and from time to time my alarm would go off and then just quit after I did a restart. Yesterday no matter what I did the tach would read 3000 at idle and when I tried to accelerate the alarm would go off at about 4000 rpms and the boat had no power. When the motor was off i noticed that the tach read 3000. So I started tapping on the tach with my hand and the needle started going down so I kept tapping until it was at zero. Well the boat ran like a champ and rpms were about where they should be. Well after a few start ups and shut downs it began to not run well and the alarm goes off yet the tach was reading correctly. Tapped on the tach anyways and it began running again with no alarm then it would come back after I slow down. Anyone with ideas?
Where can i get a replace tach or is there something else I should look at?
496ci 425hp

YYZRC

Faria will rebuild the tach if you ship it to them. 

I don’t believe that the tach is the issue. The ECM manages the performance of the engine and alarms; as far as I’m aware, there is no bidirectional data flow from the gauges back to the ECM. 

Ian

Exactly, the tach is an indicator not a control device. 

Rich_

This sounds more like a sticky needle in the gauge itself. Try to disconnect the lead at the distributor. I have not had it happen first hand but have heard of a tach grounding a distributor out and causing issues.