Mercury Tach for Dummy!

[Dslpwr81]

Hey guys. Great to register here, and hopefully will learn a ton of priceless information. This is my first boat and have never worked on boat motors, so forgive my ignorance.

I have 1982 Mercury 6cyl "Tower of Power" 115 hp Jet with a serial number of 6093314. I can find where to purchase a tach, but haven't the slightest idea on where to hook up the wires in the motor. I have searched site after site until I came upon this one. If anyone that has information on where and how.....maybe some directions....I would be very greatful. Thanks


Jason

 

[CharlieB]

Re: Mercury Tach for Dummy!

Tach selection depends on the ignition/charging system used on your motor.

Early stacked 6's with a distributor used a different tach than the late models that use ignition 'modules' and triggers. The later tachs did not run off the ignition system but count the AC 'pulses' of the charging system.

The late model tachs should have a switch on the back side that you set to the correct # of your charging system.

If you do not have a distributor and do have the two ignition modules then most any of the aftermarket outboard tachs should come with the instructions how to install, connect the grey wire from the tach to the grey wire on the voltage rectifier, red to switched positive and black to ground, set the pulse switch and be done.

 

[Dslpwr81]

Re: Mercury Tach for Dummy!

Doesn't sound difficult at all....I probably would have ordered the wrong tach too. Anyway, thanks for the info and help.

 

[Chris1956]

Re: Mercury Tach for Dummy!

Charlie, Your information is not completely correct. Distributor ignition Mercs COULD use a different tach than ADI Mercs. However, a simple wiring change that Merc made in the early 70s allowed both to share the same tach.

That wiring change is to move the brown wire on the non-distributor side of the switch box to one of the yellow stator wires, on the rectifier. The stator on the distributor and non-distributor Mercs will power a standard outboard Tachometer.

 

[Sean-Nos]

Re: Mercury Tach for Dummy!

You could always use a tiny-tack very easy to use and wire up,Lots of them on ebay,not very good looking but do the job and cheep.