87 mairner 40 hp tach problem

[skeeter87]

Hello, just got this boat and installed a tach, the tach is for a out board, And i hooked it up like i was told. But the problem i am haveing is at idle it reads 250 rpms, and wide open its gets around 2500 rpms, but in the water its different. In the water moving at idle, its reading 0rpms, and wide open on plane moving around 22 mph, its saying 1500. And i know for a fact its gotta be wrong. can some one please help me... Its got a good power and ground source, tach reading comming from a brown wire of engine.

 

[coastalrichard]

Re: 87 mairner 40 hp tach problem

Sounds like you may have the wrong pin pulse setting. Doublecheck with your instructions and service manual.

 

[skeeter87]

Re: 87 mairner 40 hp tach problem

i didnt have any instructions. And how would i switch the pin setting?

 

[coastalrichard]

Re: 87 mairner 40 hp tach problem

Look on the back of the tach for the various settings. I don't know how many pulses your ignition produces so, unless you can get more definitive info, you'll have to run through all the different settings until you find the correct one. Change from the setting you're on now to another one and run the motor.

 

[Barnacle_Bill]

Re: 87 mairner 40 hp tach problem

It should be set to 4P or 4 pulses.

 

[skeeter87]

Re: 87 mairner 40 hp tach problem

this tach has no settings.