Installing New tach question on 2-cycle

[chrisg]

I just replaced the tach on my pontoon. I replace the wires one at a time to ensure I connected them to the correct terminals.

So my question is, according to the documentation, is said to set the switch to 6P for all merc. Outboards. The switch has # of cylinders/Pulses on it.

The motor is a ?98 merc bigfoot, 60HP, 2-cycle. The diagram shows you set the switch to 1/2 of the number of poles. How can I find out what that value is for my motor?

While the documentation said to set it to 6P, I tried starting the motor, and the needle jumped to full scale as it turned over. (The thing is winterized and I can?t actually start the motor, as its out of the water, and I have no access to a hose to let me run it).

I'm hoping I won't find out that this tach does not work with a 2-cycle!
I thought you only have to select the # of cylinders.

 

[Barnacle_Bill]

Re: Installing New tach question on 2-cycle

You have 12 poles, so 6P is the correct setting.

 

[chrisg]

Re: Installing New tach question on 2-cycle

thanks for the reply, Looks like the tach should work.

I looked at the old tach, and it has a SW for # of cylinders, 2,3,4,6 with a note saying for 12 pole outboards. Wonder why the old tach had a SW depending on cylinders, and the new only for poles? and why did it just stopped working?

Guess I'll find out next year.