Automotive Tach work on 2 cycles?

[Stumpknocker]

Anybody ever do this or will the 2 cycle cause it to read twice as fast?

 

[mfarish]

Re: Automotive Tach work on 2 cycles?

It will work only if it has a 1 coil that fires all cylinders to give indication, but even then, the meter might not have the correct scale for the application. Will not work on "charge coil" types of ignitions....at least not the automotive type of RPM meter. These old auto-type tachs were made for connection to a point type ignition with an external coil.

 

[Tinkerer]

Re: Automotive Tach work on 2 cycles?

I did it on a 2 stroke single cylinder mower engine a couple of years ago but I can't remember how I did it. I do remember that I blew a tach meter hooking it up the wrong way first time around, which was expensive. I found the right way and the formula for converting the reading to 2 stroke somewhere on the internet, so you might find it with a Google search.

 

[Stumpknocker]

Re: Automotive Tach work on 2 cycles?

mfarish, we are talking about a 1986 Evinrude 225. Obviously it probably has 6 coils.... so the reading of 1000 rpms more than the onboard OMC tach is suspect?<br /><br />By the way mfarish.... I used to live in Lenoir and go to church in Kings Mountain! My birthday is the 7th of Feb, 52... what are the odds?<br /><br />Small world indeed.

 

[Stumpknocker]

Re: Automotive Tach work on 2 cycles?

Bump!

 

[Paul Moir]

Re: Automotive Tach work on 2 cycles?

How did you attach it? Is it a 'clip onto the spark plug lead' inductive pickup type, or one that's supposed to read the pulses on the input of the car's ignition coil? Outboard tachs work off the charging circuit rather than the ignition system, and just about all OMC engines whether they be 4, 6, or 8 cyl (yours included) produce 6 pulses per revolution.

 

[ANDREW SMITH]

Re: Automotive Tach work on 2 cycles?

Clip the inductive pick-up to any skark plug lead, read the rpm, then halve it. For example;if your rpm reads 1800 then your two stroke outboard is running at 900 rpm. Hope this helps!

 

[Stumpknocker]

Re: Automotive Tach work on 2 cycles?

I will call George tomorrow and find out exactly how he did the hookup. I can't imagine that the readings would be accurate.

 

[shuckbo]

Re: Automotive Tach work on 2 cycles?

Hi , can somone please advise me how many pole tach do i need for a 1988 V6 225hp looper , i want to replace the one i have , many thanks steve

 

[seahorse5]

Re: Automotive Tach work on 2 cycles?

Originally posted by shuckbo:<br /> Hi , can somone please advise me how many pole tach do i need for a 1988 V6 225hp looper , i want to replace the one i have , many thanks steve

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