Can't get 40 yamaha tach working!

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tmillsap80

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I have a 86 40 yamaha 2 stroke been trying to hook up a tachometer, but can't seem to get it. I bought a rectifier to put on it it has 2 greens, 1 red, 1 black. I hooked green to green coming from under fly wheel. Red to battery, and black to motor block. still no tach.:( It is charging the battery but tried hooking the tach signal wire to the pigtail on the green wire for signal but tach don't show any change. tach is hooked to battery, grounded, and signal hooked up. Does any body know whats up? Need help!
 
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kurt5490

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Re: Can't get 40 yamaha tach working!

i wish i new im trying to find a tach to do the same exact deal on a 40hp mercury. sounds the same. is it a digital tach? or dose it have a needle?
 
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tmillsap80

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Re: Can't get 40 yamaha tach working!

It is an analog tach with a needle, but fixing to forget about it and hook up a tiny tach that is digital and you just wrap the wire around the plug wire. If I can't get this one working. I'd rather have the analog.
 
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kurt5490

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Re: Can't get 40 yamaha tach working!

let me know how that works for you, i didnt purchase a tach yet but if the digital one your talking about is easier to install and works well i may also try that
 
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99yam40

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Re: Can't get 40 yamaha tach working!

people need to know what type of tach it is to be able to answer any questions about it
 
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tmillsap80

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Re: Can't get 40 yamaha tach working!

Teh tach I'm trying to hook up is a Faria tach it has 3 posts on the the back signal, ground, and positive. has 2,6,8,10,12 pulse dial switch I put the tach on a friends boat motor same motor as mine same year and everything and the tach works, but put it to mine and nothing. So I ordered a rectifier, and put a new lighting coil on it. what could it be?
 
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99yam40

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Re: Can't get 40 yamaha tach working!

being a 86 is it a 2 cylinder or 3?
The 2cyl has 4 poles 2 pulses and the 3 cyl has 6 poles three pulses from what I have read.
You stated that the tach has a switch for 2-12 pulse, are you sure it is pulse and not pole?
I have asked questions on line about the signal going to the tach and all I have found out so far is that it is AC voltage, nothing about how much at any certain RPM.
Have you tried measuring the signal on the motor that it did work on and compare that to the signal on your motor?
Are you sure that the ground wire is making good connection to the motor?

here is a link to the Faria web site that may help

http://faria-instruments.com/site_manuals/IS0100_Tachometers.pdf
 
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tmillsap80

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Re: Can't get 40 yamaha tach working!

Thanxs 99yam40
My motor is 86 3 cylinder. I have not check the signal, I would like to know how to check signal, but all I know is that I am getting voltage but that that is it. Your help is greatly appreciated.
 
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