What mercury rev counter do i need?

[martin33100]

Hi, I have just bought a 1997 Avon Rib with a 1997 Mercury 90 on it, I would like to add a mercury rev counter as it doesn't have one, does this wire into the control box on the side of the consol? and is there any type of mercury gauge I require?

cheers martin

[9D280]

If you want to go "proper Merc" there should be a short lead with a plug dangling out your control box, It will plug straight in there.

No idea what your electrical sklillsd are like, but plumbing in any old (non digital) Tacho should be feasible. (I'm using a Suzi tacho on My merc)

[martin33100]

Originally Posted by 9D280

If you want to go "proper Merc" there should be a short lead with a plug dangling out your control box, It will plug straight in there.

No idea what your electrical sklillsd are like, but plumbing in any old (non digital) Tacho should be feasible. (I'm using a Suzi tacho on My merc)

My electrical skills should be ok for this, I work on trains every day

[9D280]

In that case.....

You really only need 3 wires, +, - & Signal. (and a lamp supply if you want to see it in the dark!)

The tacho signal wire for the Merc should be Grey, the +/- are the usual red / black, but there may be a trace colour on the + as it's switched. If there's no gray, break into the controls, it will be one that goes straight from the engine loom to the short plug loom. Can trace it back to the rectifier in the engine to be sure)

For reference (in case you get someone ellse's tacho) colours are: Yam - Green Suz, Yellow. I think OMC & Honda use Gray too.


Any non digital gauge should work, you may need to set the switch on the back to the right number of poles. it's pretty obvious when its wrong (e.g. idling at 400 / 1500 RPM or flat out at 3.5K or off the scale)


The tacho basically counts alternator pulses, most have two or three positions for different # pole variants.

[martin33100]

Originally Posted by 9D280

In that case.....

You really only need 3 wires, +, - & Signal. (and a lamp supply if you want to see it in the dark!)

The tacho signal wire for the Merc should be Grey, the +/- are the usual red / black, but there may be a trace colour on the + as it's switched. If there's no gray, break into the controls, it will be one that goes straight from the engine loom to the short plug loom. Can trace it back to the rectifier in the engine to be sure)

For reference (in case you get someone ellse's tacho) colours are: Yam - Green Suz, Yellow. I think OMC & Honda use Gray too.


Any non digital gauge should work, you may need to set the switch on the back to the right number of poles. it's pretty obvious when its wrong (e.g. idling at 400 / 1500 RPM or flat out at 3.5K or off the scale)


The tacho basically counts alternator pulses, most have two or three positions for different # pole variants.

Thanks for the help, I may try and find out who made the water presure and fuel gauge that is allready on the rib, they may do a revo counter to match, I know they are not mercury, I have also seen some nice Teleflex gauges, what are they like?

[9D280]

There's a very high chance they will! I've heard people say the older ones have a habit of fogging up. Ssearch the posts, I've seen a few discussions about them on here.

[Turbodiesel]

Mercury Part number....
79-859674A1

Black face and bezel. 0 - 6000RPM.

[spartacus]

Originally Posted by martin33100

I have also seen some nice Teleflex gauges, what are they like?

Teleflex make fairly good gauges, but not a patch on OEM products.