TOPIC: Need tach for 65 Merc 1000

I am looking for a tach to use with an Aristocraft Funliner with a restored 1965 Merc 1000 motor. I would very much appreciate any guidance you all could give me as far as finding a tach that will work with this motor.

Thanks, Dave

any new tack . they work off of the alternater easy to hook up. teleflex has them for $50.00 and up.

I believe some of the guys can explain how to use an automotive tach reading off one of the coils, but I prefer to use a new TeleFlex tach that comes in a variety of colors, requires 12v, a ground, and a sender wire connected to either of the (2) yellow wires at the rectifier coming down from the 12 pole stator under the flywheel. Set this style tach on the 6 pulse setting and you are good to go.
If your internal harness does not have a tach sender wire built in simply run one from the rectifier (either yellow wire terminal) through the hole in the lower pan placed there to access the bottom screw on the bottom fuel pump, and run this wire along side your harness going up to the controller & dash.
Just google 'TeleFlex gauges' and you'll see the options. Many marinas that outfit boats with new motors and related gauges usually have a box full of used tachs they have removed from the boat when installing the new stuff. Ask for a 12v 6 pulse tach and they should have a bunch for around $30-60 used ones.
Thom

Working on similiar tach, where does the ign. wire go to.No paperwork came with unit.PO had 3 wires hooked up to send unit that appear to be postive wires for horn,lights and fuel gauge.Wiring was not completed when I bought boat,I have task of finishing it with no schematics.Not tying to jack thread just similiar topic.

Mr 88,
The back side of the tach should be labelled 'IGN' 'GRN' 'SEND'.
The 12v(+) goes to the IGN.
Engine or battery ground (-) goes to GRN.
The SEND needs to go to a terminal on the rectifier that has a yellow wire from the stator on it.
Be sure and do voltage and continuity tests on any wires you consider putting on the tach to avoid damageing the tach.
If all the wires are connected right and the tach won't work - it is possible the rectifier or stator have failed and are not putting out 12v(+). The rectifier failure is most common.
Thom

The only wiring harness from the stator down is wrapped in green with only two wires in it that appear to be the same color, they both hook up to a rectifier? with one bolted on top and the other bolted right below it.

that is the one to hook to. either one.

Thanks guys.So the IGN goes to 12V and is it okay if it's a hot 12V all the time or hot only when you fire up the engine.I have a Teleflex and was also wondering about the bottom display,looks like a odometer but I would guess that it is a hour meter,thats why I ask about the hot hookup.If not hot where do you hook her up to. Will give it a shot this week,been raining for almost 3 days straight and there calling for it to stop by Friday,maybe.I would like to put the ears on,don't feellike pulling it out of the garage when it's 50 and wet.It's been one of the worst spring's for quite a few locations.Flooding Tornados,cold and just dragging on.

hook up to on off with the key 12V.