how to hook up this cheapo tach

[jasperpso2]

i ordered this tach on ebay

it only has one wire, and says to wrap around the spark plug wire... i am assuming any one will work? also, i have to configure it for sparks per revolution.. it can be set to two sparks for every revolution, one spark every revolution, or a spark every other revolution.. for my mercury 50 hp 4 cylinder 2 stroke, which of these settings is the correct one? i am guessing the one spark every revolution is correct? thanks for any help!

 

[jasperpso2]

Re: how to hook up this cheapo tach

also, can i extend this wire to reach my pontoons dash, or should i mount it in the rear of the boat?

 

[RicMic]

Re: how to hook up this cheapo tach

I have the same tach, it works just fine, but hard to read in direct sun. For a two stroke set it one spark per revolution. I don't know about extending the wire, I wondered the same thing, but my guess is no, you could try it, but its working on very low current, so I doubt it can be extended far. Any sparkplug wire will do, they all fire one time per revolution on a two stroke.

 

[jasperpso2]

Re: how to hook up this cheapo tach

thanks, i am gonna hook it up tomorrow, if the weather is good.. i cant wait to see how it works. i still have the original prop on from when i bought the boat last month, i wanted to get the tach hooked up to see were i was, before putting the new one on unnecessarily.. i dont think i am hitting 5k rpm, but we will soon see.

 

[RicMic]

Re: how to hook up this cheapo tach

I wrapped the end of the tach wire 3-4 times around the plug wire and secured it with electrical tape, but figure out how to route the wire first. I mounted my tach with self stick velcro, so I have the option of moving it.