Tachometer hookup to 90hp 1989 Merc Outboard w/ Quicksilver remote (w/ pic)

[intothewild]

Hello,
I want to add a tach to my boat (1989 90hp merc w/ quicksilver remote). I have the quicksilver remote with the tach plug. I have a few questions:
Will any 5 prong mercury tach harness work?
Should the brown wire in the pic be connected to anything? (it comes from the tach plug and terminates at the blue/green thing with the cable tie around it).
Can I use any tachometer or does it have to be a certain type?
Thanks,
Ryan

 

[intothewild]

Re: Tachometer hookup to 90hp 1989 Merc Outboard w/ Quicksilver remote (w/ pic)

I found the harness and ordered it and I think I determined that the brown wire won't matter for the tach.

Still haven't figured out what type of tachometer to buy - its a 3 cyl 2-stroke engine I believe. Any suggestions?

 

[gfbiii51]

Re: Tachometer hookup to 90hp 1989 Merc Outboard w/ Quicksilver remote (w/ pic)

Ryan,

I have exactly the same question. I have a 1982 70 hp 3 cylinder. Hope someone knows a simple answer.

George

 

[j_martin]

Re: Tachometer hookup to 90hp 1989 Merc Outboard w/ Quicksilver remote (w/ pic)

The tachometer runs off the alternator (stator), tapped in at the rectifier or regulator. It doesn't make any difference what the cylinder count is, just the alternator pole count, which is 12 I believe, or 6 pulses per revolution.

An automotive type tachometer won't work. Mercury stock, or any tachometer said to be equivalent to it will work.

hope it helps
John

 

[intothewild]

Re: Tachometer hookup to 90hp 1989 Merc Outboard w/ Quicksilver remote (w/ pic)

Thanks John - definitely helps. gfbiii51 - I found that my Merc has the 12 pole strator and I'm guessing yours does to ( everything I read pretty much said all Merc outboards from our era have the 12 pole strator).

My remote has the plug (in the pic above) and I ordered a harness for it - should be a simple connecting of the harness to the tach, the tach backlight to the light switch and done.

Now the challenge is finding a 12-pole tach that won't break the bank! Most I've seen have been in the $150 to $300 range. With all the old boats laying around there has to be something out there

 

[gfbiii51]

Re: Tachometer hookup to 90hp 1989 Merc Outboard w/ Quicksilver remote (w/ pic)

Thanks John and Kyle.