# Yamaha 70 tach



## Capt_David (Jul 14, 2008)

My tach pegs out to 7K when I start the motor. The oil light is amber and SHOULD be green as the tank is full. I have a spare tach and checked it. NOT the tach same problem. I have checked all the wires twice and the grounds twice. This has me stumped...Also have a spare rectifier and it not that...Any ideas?


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## Brett (Jul 16, 2008)

Any of the tachs I had problems with, the reason was usually
one of three things: dead tach, incorrect setting of the calibration, resistance in the wiring.
You tried another tach...same results, so I'd say settings and tach are ok.
I'd be looking for corrosion/resistance in the wiring
or a failing stator that's not producing the proper voltage.


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## Capt_David (Jul 14, 2008)

Thanks Brett, I will put a meter on it later..


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## Capt_David (Jul 14, 2008)

Hey Bret,
It is a stator...Do you know where I can get on cheap..


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## Brett (Jul 16, 2008)

No cheap yamaha stators,
$300 plus for a new one is what I find on the web.


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## Capt_David (Jul 14, 2008)

Ebay is the way, I will have my new to me 50 buck one in three days....Time to get out the tools..


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## aflatsnut (Feb 12, 2010)

I sent an Email to my Bud the Boat Doctor, he may have a used one. I'll know tomorrow.He has a repair shop and used parts. He's honest and legit. 

Bob


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## Capt_David (Jul 14, 2008)

I found a new/used one on ebay for 60 bucks...You dont get them that cheap anywhere.


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## aflatsnut (Feb 12, 2010)

Good job. Just another note. The tach works off the charging circuit and an easy check would be to meter the voltage at your battery with engine off then start it and meter it again. If voltage goes up then stator is working, unless just one diode is bad then charging would be slow. I don't have specs on stator output to give you voltage numbers though.

Good luck.

Bob


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## aflatsnut (Feb 12, 2010)

Good job. Just another note. The tach works off the charging circuit and an easy check would be to meter the voltage at your battery with engine off then start it and meter it again. If voltage goes up then stator is working, unless just one diode is bad then charging would be slow. I don't have specs on stator output to give you voltage numbers though.

Good luck.

Bob


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