HELP!!! tach pulse on 97 force 75?

00buckshot

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Jan 31, 2012
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Guys this forum has been very helpful to me in the past with my older force! Now i have a 97 force 75 3 cyl 2 stroke. I'm trying to install a tach on my boat now as it doesn't have one, I have all the wiring for it figured out I just need to know how many pulses this engine puts out to know where to set my tach dial at. I have read that it may need to be set on 6 pulses? Is this correct? If not someone please point me in the right direction, much appreciation to you hardcore guys!!!
 

pnwboat

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Oct 8, 2007
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Re: HELP!!! tach pulse on 97 force 75?

Your setting should be 12 pole or pulses. You have a 12 pole stator.
 

00buckshot

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Jan 31, 2012
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Re: HELP!!! tach pulse on 97 force 75?

ok, my tach doesn't say anything about 2 stroke it shows number of cylinders or pulses, so if it will set to 12 pulses then it should be fine correct?
 

pnwboat

Rear Admiral
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Re: HELP!!! tach pulse on 97 force 75?

Yes, set it to 12 pulses and you should be good to go.

NOTE: Cylinders and pulses are two different things on the tach settings. Most automotive 4-stoke tachs have a setting for the number of cylinders. Outboard tachs typically have a setting for the number of pulses. If you're not sure about what type of tach you have, you may have "experiment" with the settings. It won't hurt anything, but the reading will be off. If you set the tach to 12 pulses and you're seeing 2000 RPM at idle on the tach, obviously that is wrong. It probably should be set to the 6 pulse setting. Idle should be somewhere around 600 - 900 RPM range. If it reads too high, then set it to a lower pulse setting.
 

00buckshot

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Jan 31, 2012
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Re: HELP!!! tach pulse on 97 force 75?

Thanks alont man, I'm not even sure if i have a 12 pulse setting but i will look, its a little older tach but looks to be in great condition so I'll experiment with it, mainly trying to get a tach reading to dial in my prop
 

achris

More fish than mountain goat
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May 19, 2004
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27,468
Re: HELP!!! tach pulse on 97 force 75?

Yes, set it to 12 pulses and you should be good to go.

NOTE: Cylinders and pulses are two different things on the tach settings. Most automotive 4-stoke tachs have a setting for the number of cylinders. Outboard tachs typically have a setting for the number of pulses. If you're not sure about what type of tach you have, you may have "experiment" with the settings. It won't hurt anything, but the reading will be off. If you set the tach to 12 pulses and you're seeing 2000 RPM at idle on the tach, obviously that is wrong. It probably should be set to the 6 pulse setting. Idle should be somewhere around 600 - 900 RPM range. If it reads too high, then set it to a lower pulse setting.

Agree with you about cylinders and pulses being different. However, if you are seeing 2000 at 'idle' with it set to 12 pulses, you would need to set it to 24 pulses to see the indication drop to half that, not 6.

But I have never seen an outboard alternator use anything but 12 pulses, especially 'Mercury' engines (of which a Force is).... Depending on the brand of Tach, it may just have 1,2,3,4 on the back, in which case you'll need the manual to know which is what, or just set it to each one and see what you read. You won't hurt the tacho....

Chris........
 
Last edited:

Jiggz

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Oct 23, 2009
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3,817
Mayron, the signal source wire for the tach is the gray wire coming off the voltage rectifier/regulator
 

GA_Boater

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May 24, 2011
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I have the same motor , what cable did you use for the sender ...

Welcome aboard, mayron. This is why we ask that you do not reply to old topics. The original poster you are asking for an answer, has not been here in over a year. You should start a new topic with your question instead of tagging on to an old topic. Thanks.
 

NYBo

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Crud! I completely missed the date the thread was started.:redface:
 
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