No Tach - Should I add one?

[Eddie Mullins]

More newbie questions. I have seen a number of posts referencing rpm ranges, but I don't have a tach on my "new" boat. Do I need to add one? If so is it any easy install?

 

[JB]

Re: No Tach - Should I add one?

Not worth the trouble unless there is an engine on the boat. How valuable it is depends on the engine.

Does your boat have an engine? What sort of engine?

 

[Eddie Mullins]

Re: No Tach - Should I add one?

It has a 1970's 500 model Mercury 50 hp outboard.

 

[Silvertip]

Re: No Tach - Should I add one?

Every outboard and I/O engine manufacturer specifies a maximum wide open throttle RPM range for its engines. If Merc says the WOT rpm for your engine is 5000 - 5500 RPM that means with an average load your engine should have a prop installed that allows that to happen. If the engine can't reach that rpm it is being overworked (overpropped) and it can be damaged. If the engine runs faster than recommended (underpropped) it can also be damaged. So without a tach you have no idea whether or not you have the correct prop. Now you should be able to answer your own question. To add a tach you drill a hole, connect three wires (four if you want the light) and away you go. It's as simple as following the directions.

 

[JB]

Re: No Tach - Should I add one?

Yup. Sorry for pulling your leg, Eddie, but I needed to make a point.

A tach makes your engine a lot more usable and makes it possible to select the best prop and the best trim.

Good luck.

 

[ebry710]

Re: No Tach - Should I add one?

More newbie questions. I have seen a number of posts referencing rpm ranges, but I don't have a tach on my "new" boat. Do I need to add one? If so is it any easy install?

You do not need to add one.........but I agree with the people above. They are real helpful.

Installing one should be a matter of:
1) finding your parts manual and buying the one specified or talking to your Mercury parts guy
2) drilling into your dash
3) plugging or screwing in your harness

 

[superjay]

Re: No Tach - Should I add one?

You can get an inductive tach as well. Which is an extremly easy install, all you need to do is wrap a wire around one of the spark plug leads and run it to the tach. They are self powered and usually include an hour meter and are usually much cheaper then a mechanical tach.

 

[tmcalavy]

Re: No Tach - Should I add one?

Tiny Tach makes a good, small, portable inductive tach.

 

[Eddie Mullins]

Re: No Tach - Should I add one?

Thanks for the replies. It sounds like the inductive tachs may be simple enough for even me LOL..

I just got in my aftermarket manual for the motor. I believe it indicated there is a plug on my throttle control assembly for installing a tach? I'll have to look at it again.

The boat is still at my dad's currently. My son and I will be picking it up next weekend. Can't wait to get it here and hopefully in the water soon!