Buying a new tachometer

Jerry999

Cadet
Joined
Sep 7, 2018
Messages
14
I have a 2003 90 HP Mercury on a 171 Sea Fox. The tach doesn't work so I'm looking to buy a new one. Since it's a 3 cylinder carbureted engine, is there anything special that I need to know? I've been reading a lot about pulses and settings so I wanted to make sure to get one that works.
Thanks for any help.
 

Jerry999

Cadet
Joined
Sep 7, 2018
Messages
14
Not Really, I understand about the grey wire and power to the tach, but thats about all.
 

Jerry999

Cadet
Joined
Sep 7, 2018
Messages
14
If I ran the engine what reading would I expect on the grey wire and what setting would I set on my volt- ohm- amp meter?
 

Jerry999

Cadet
Joined
Sep 7, 2018
Messages
14
OK Thanks. I have both a analog and digital meter so if I use the analog then I wouldn't need a DVA adaptor. I will check it out tomorrow. Still if I need a new Tach will any Marine 8000 RPM tach work and what would I set it to. The old one was set between 4 and 5 which wasn't any help. I just bought the boat and all gauges look original.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Tachometers are pretty universal. Just don't buy one at an auto store because those are typically for cars only and they will not withstand moisture. You can get a tach right here on IBoats. Click SHOP at the top of this page.
 

robsalik24

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Joined
Oct 2, 2018
Messages
11
You have to buy a marine outboard tach only. I just recently found this out after buying an automotive one just to see what the revs I was turning. the signal coming from the pick up on the motor is different on an outboard motor than it is on an automotive type engine / inboard outboard. Farrah makes tachometers for outboard. Easy to install easy to set up worth 80 bucks.
 
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