Need Help on new Tach

[rfins]

Boat a used boat and the tach did not operate properly......it would get stuck around 3500-4000 rpm and would not register higher.
I bought a new tach from Faria, and when I installed it I set the little dial on the back at #4, same as the old one was.

When I took the boat out it would show about 7000 rpm at about 1/2 throttle.
I called Faria and they said try setting the dial to #5, the boat is still showing about 6400 at 3/4 to full throttle.

What if I switch the dial to #6...….does each number lower the tach reading ??

I have a 2003 Yamaha F115 four stroke.
I don't know what the pulse output is or what number I should set the dial to.

Any help would be appreciated.

 

[Sea Rider]

Play with dial numbers till a lower rpm reading is obtained. That OB runs 4500-5500 wot rpm range if not mistaken.

Happy Boating

 

[Silvertip]

That numbered dial represents the number of pulses from the alternator. If your engine has a 12 pole alternator, and I think it does, the dial would be set to "6". A 12 pole alternator produces 6 pulses for each engine revolution. Those pulses have nothing to do with the number of cylinders or two stroke/four stroke.

 

[Chris1956]

Your motor is new and common enough for Faria to tell you what setting to use, unless that tach is incompatible with your motor. You should not need to perform trial by error.

Gee, their web site should tell you, under applications for their tachs.