Tachometer

About using jet ski motors to power small boats

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marksa1458
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Tachometer

Post by marksa1458 » Sun Sep 30, 2007 11:43 am

I would like to install a tachometer in my boat - The tachomter I have has three terminals and a rotary switch

The terminals are Ignition, Ground & Send

Ignition and Ground are easy, but I'm not sure where or how to connect the send wire.

Also, I'm not sure what to set the rotary dial to - there are a number of settings for cycles/pulses..

Any help would be appreciated!
Both the below websites detail my build progress.

http://dynojet.fateback.com/Index.htm
or
http://www.geocities.com/marksa1458/

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steve crawford
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Location: K.C. MO.

Post by steve crawford » Mon Oct 01, 2007 5:47 am

I don't know . You better go to pwctoday.com or call the dealer on that one, these little jetskis don't have tachs.

terrymc
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Post by terrymc » Mon Oct 01, 2007 2:02 pm

I didn't put a tach in my boat, just for this reason. I've got a Kawasaki manual, and in the RPM Limiter section it tells you to "attach a tachomoter" but it never tells you how! Obviously it can be done, but I could never figure out how...

Peace,

TRM

Brian Eager
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Post by Brian Eager » Tue Oct 02, 2007 4:02 am

"ignition" means 12v positive, switched by the ignition circuit.
"ground" means just that, chassis, earth, 12v negative.
"send" means hooking a sensor wire to one of the spark plug leads. not to the spark circuit, usually it just lays alongside, outside the insulated jacket, but picks up the spark signal by induction.

the cycle/pulse thing lets you use the tach on two or four cycle engines. Beware! Some newer four cycle engines actually fire the plug on every revolution, just like a 2 cycle. if the reading seems to be double what it should be, change the switch setting.

Talk to your local small engine repair guy, he should be able to clear it up for you.
Noah was a first-time boatbuilder

Gary McCusker
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Location: Louisville,KY

Post by Gary McCusker » Fri Oct 05, 2007 6:28 pm

Try tinytac.com. They can set you up a tac for what ever you need. I got one on my 25 Yamaha. Works as a hour meter and tac all in one. Tac updates it's self every 3-5 seconds. Very nice people to deal with. McCusker

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M_Holmes
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Post by M_Holmes » Wed Dec 19, 2007 9:09 pm

Hi,

I've seen a couple of tachometers on ebay with an inductive pickup that were supposed to be adjustable for use on a 2 or 4 cycle engine. That looked like a promising solution to me...

One other possible solution I was looking into was an outboard motor tachometer... Most of the aftermarket outboard tachs I've seen specify a number of "poles" not cylinders, so I'm guessing that has to do with the number of magnets in the flywheel, like a "4 pole" would have 4 magnets, etc?

Since I don't really see any of them specifying a number of cylinders or anything, I have to assume they are driven by a pulse from the charging system?. Seems like you would be able to tap into the wire from the magneto back to the battery or something???

I have been thinking about this very question since I started building my squirt, lol. I'm sure you could get a regular outboard tach to work somehow. I need to get a hold of installation instructions for a common universal outboard tach, then I'd be able to say with some certainty whether or not it would work.

take it easy,

Matt

marksa1458
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Post by marksa1458 » Thu Dec 20, 2007 8:29 am

Attaching a wire to the spark plug didn't produce any output on the tach.
Both the below websites detail my build progress.

http://dynojet.fateback.com/Index.htm
or
http://www.geocities.com/marksa1458/

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Caber-Feidh
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Post by Caber-Feidh » Tue Dec 25, 2007 11:57 am

What brand/type of tach is it? This may seem obvious, but you are not going to be able to make (most) automotive tachs work with CDI.

marksa1458
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Location: Massachusetts
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Post by marksa1458 » Wed Dec 26, 2007 7:46 am

Right now - my boat and all supplies are in storage for the winter. I will have to dig out to get the brand name. The tach iss branded for marine use.
Both the below websites detail my build progress.

http://dynojet.fateback.com/Index.htm
or
http://www.geocities.com/marksa1458/

Gary McCusker
Posts: 47
Joined: Sun Mar 27, 2005 2:57 am
Location: Louisville,KY

Post by Gary McCusker » Sat Jan 05, 2008 4:14 pm

Trust me. For $40 dollars go to tinytac.com. These people will set you up w/ what ever kind of tac you need for any installation. McCusker

marksa1458
Posts: 166
Joined: Mon Sep 12, 2005 5:57 am
Location: Massachusetts
Contact:

Post by marksa1458 » Mon Jan 07, 2008 8:51 am

I will check them out - Thanks for the help!
Both the below websites detail my build progress.

http://dynojet.fateback.com/Index.htm
or
http://www.geocities.com/marksa1458/

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