TOPIC: Add a Tachometer to 1962/63 Mercury 500

I want to add a tach before I take this thing WOT, can you connect a modern tach to it or does it have to be an older model? My control doesn't have a tach output so any help on wiring it in. Hopefully this post will help others in the future so add lots of keywords since I can't find much on Google.

Either an old tach for a 4cyl mag OR a modern tach (Teleflex) that runs off the charging system if you have it on your motor. I may have an older tach.

I would like to get this set, I want to do modern technology with the old style, I am going to mount my 7' tablet for navigation and GPS but I think it will make a flip down panel so it's not seen when it's not being used.
That white set says it works with 4/6/8 cyl so guess it will work off the charge circuit to get the pulse, I assume they mean the recified stator DC pulses.

You are correct. set the right pulse for the motor.

firstfibre wrote:

I would like to get this set, I want to do modern technology with the old style, I am going to mount my 7' tablet for navigation and GPS but I think it will make a flip down panel so it's not seen when it's not being used.
That white set says it works with 4/6/8 cyl so guess it will work off the charge circuit to get the pulse, I assume they mean the recified stator DC pulses.

Actually its taken off the stator Non rectified AC, not the DC.

missed the DC hook to one of the yellow wires from the stator

Thanks guys, had the boat on the ocean today was a blast

You can use the late model tach on the 4c setting too by attaching the send wire to the magneto kill terminal.
Or on the 4p if the sender wire is connected to either of the yellow wires at the rectifier if your 500 has a charging system.

(The early 500 has an 8 pole stator)
doc

Thanks as always Doc, it does have a charging system and it's great to have it out and it's running pretty good I assume, need to get a tach on it before I explore more throttle but 25mph is still fun.
I will be out there next week, I am building a list of parts, the cam in the mag has some burnt marks and one of the plugs was core and gap bridged so I think that was his missing problem. have not dissembled yet.
Do you have timing belts for the 450 & 500?
Thanks
Steve

Yuppp,....Lots of them:-)
doc

Pulled this tach off my other boat, it says "POS" on one terminal and "NEG" on the other, Does the POS still need to come off the yellow on the recifier? do I have to run another wire all the way from the motor or can I tap in somewhere on the cable or throttle box?