Autometer tacho compatible with 60HP Mercury?

[twr7cx]

I'm looking at Auto Meter Pro-Comp Marine Ultra Lite Silver
3 3/8" 7000 RPM Tachometer with digital hourmeter (http://shopping.rexmar.com/Merchant...T200890-33&Category_Code=ProCompMarineULTachs) for my boat with a 1993 Mercury 60HP. Can anyone confirm that it will work with the outboard, even though it's only 3 cylinders?

 

[Chris1956]

Re: Autometer tacho compatible with 60HP Mercury?

Generally auto and outboard tachs are not interchangeable. OB tachs count the stator pulses, while auto tachs count coil pulses. You might get lucky, but OB Tachs are not too expensive.

 

[Silvertip]

Re: Autometer tacho compatible with 60HP Mercury?

An outboard tach counts stator pulses (6 of them from a 12 pole stator) with each revolution of the engine. An automobile engine is a four stroke so the auto tach counts coil pulses which occur once every other rev. But since there are an abundance of coil systems available today, such as separate coils for each cylinder, one coil for all cylinders, etc it is hard to tell how adjustable that tach is. If its for a single coil system, then the number of cylinders enters the picture since a 4 cylinder produces two pulses per rev, a six cylinder would produce 3 pulses per rev, and a V8 would produce 4. On an outboard it doesn't matter how many cylinders the engine has. Buy an outboard tach that will be cheaper and you know it will work. You can buy a separate hour meter for $40. I haven't checked recently, but I think either Faria or Teleflex actually offers a tach with an hour meter.

 

[twr7cx]

Re: Autometer tacho compatible with 60HP Mercury?

The tacho I've linked to above is a MARINE tacho though - but does this mean it's made for big boats with inboards not little outboards like mine?
Reason I'm asking is that I've already got a factory tacho and speedo in my boat, but liked the look of the autometer stuff, so was just going to replace it. Obviously won't bother if it's too much of a hassle.

 

[Silvertip]

Re: Autometer tacho compatible with 60HP Mercury?

It isn't a matter of hassle. It's a matter of will it work! If it's an Autometer, I'll bet its for an inboard or I/O both of which use automobile based engines. If the description says it can be used on four, six, or eight cylinder engines, its an auto tach. For marine use it would have a switch on the back that has some numbers corresponding to stator pulses (such as 4P, 5P, 6P). I really think you have a tach for an auto engine. But -- I've been wrong before. My excuse will be that "I couldn't see the tach". Give us a model number and we can check. And you also haven't told us if your 60 HP motor is a two or four stroke.

 

[twr7cx]

Re: Autometer tacho compatible with 60HP Mercury?

And you also haven't told us if your 60 HP motor is a two or four stroke.

She's 2 stroke.
Yeah, I understand what your saying. This is my first boat, so still a little new to all this. What does I/O mean by the way?
I was just looking at some other gauges avaliable to us here in Australia, and I've found some others I like that are made for the outboard, so problem solved now - and they're avaliable locally, as opposed to the Autometer, which I was going to have to order from the US.