2015 Larson 195 LX V6 4.3 MerCruiser

Electrical and electronic topics for small boats
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Joined: Tue May 15, 2018 10:23 am

2015 Larson 195 LX V6 4.3 MerCruiser

Postby FranceT » Tue May 15, 2018 10:27 am

I have a 2015 Larson 4.3 MerCruiser V6 220-HP. The engine Is running 5200-RPM at boat speed 40-MPH, and WOT hits 6000-RPM. On the back of the tachometer a dial is labeled 1 through 6 on dial, and is set to 1. Should this be set to 3 for a V6?

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Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula

Re: 2015 Larson 195 LX V6 4.3 MerCruiser

Postby jimh » Wed May 16, 2018 8:19 am

Many tachometers are made with variable calibration settings. Usually the calibration number corresponds to the number of tachometer signal pulses that are generated in one engine crankshaft revolution. A setting of one would suggest one pulse per revolution. Setting the calibration to 3 would suggest three pulses per revolution. If those inferences were true for the tachometer you have, then if you are now reading 6000-RPM when set to CAL = 1, by changing to CAL = 3 the new reading would be 6000/3 = 2000. That seems much too low to be the true engine speed.

Check with the tachometer manufacturer for advice on the proper setting with the engine you have.