Adding a tach

[TAC_Double]

I was wondering if anyone could tell me if it is possible to add a tach to my engine. it's a 75 40hp 40555C. It would be nice to have. Also maybe a water temp or pressure. Is it possible?

 

[Rikster]

Re: Adding a tach

Just adding a bump up

 

[emdsapmgr]

Re: Adding a tach

You could remove the cylinder head cover and tap a hole in it, for the water pressure outlet. The engine has points, instead of the cd ignition. I will venture a guess that there is no gray wire feed on a points setup- to drive a tach. You can mount an external sender to the head to measure temps.

 

[F_R]

Re: Adding a tach

It does have an alternator, however I don't know how many pulses. That would be the deciding factor in whether a tach would work on it.

 

[ezeke]

Re: Adding a tach

The teleflex installation instructions list yours as a 5 pulse tach on page 6. You can contact their Tech Support group and they are very helpful. iboats sells the teleflex line of tachometers.

http://www.teleflexmarine.com/library/instructionmanuals/99320%20rev%2010%20Tachometer,.pdf

http://www.teleflexmarine.com/cgi-bin/page.cgi?site=gauges&type=us&page=1012

BTW, My wiring diagram for your motor does not show a gray pulse lead running through the main harness to the control. You may need to run your own gray pulse wire to the tach from the yellow and gray wire off the alternator at the terminal block. You will also need a black ground wire running from the engine block. You can take the 12V positive purple lead off the ignition switch so that the tachometer is enabled when the switch is on.

 

[TAC_Double]

Re: Adding a tach

Thanks for all the info. You guys know your stuff!