Tach

[Mavric]

Hi i have a 1989 mariner 50 hp 4 cylinder 2 stroke outboard on my boat can anyone tell me how to wire up a tach to it and where , with pics please it's driving me nuts now and how many poles if i can only use a boat tach or will any rev counter do it as long as it dose 2 stroke and 4 stroke their are a few on ebay .I tried wiring it yesterday black to earth on battery red to positive on battery and i connected the signal wire to the only grey wire i could find didn't work ?.

 

[Big John]

Hi i have a 1989 mariner 50 hp 4 cylinder 2 stroke outboard on my boat can anyone tell me how to wire up a tach to it and where , with pics please it's driving me nuts now and how many poles if i can only use a boat tach or will any rev counter do it as long as it dose 2 stroke and 4 stroke their are a few on ebay .I tried wiring it yesterday black to earth on battery red to positive on battery and i connected the signal wire to the only grey wire i could find didn't work .

It depends on the type you have bought.

You may have bought the type for a petrol engine that the single wire connects directly to the contact breaker points on the coil but on an out board you may not be able to do that as the coil is inside the fly wheel. Or you have bought one for a diesel engine and the single wire goes to the "W" terminal on the alternator.

At one time you could get a tachometer that used 12vdc and a single wire that was wrapped around the HT lead and with the internal switch you set the reading for 4,6,8 etc cylinders. Check out your local auto shop.

 

[spannerman]

Do you have a control box (throttle) with a short lead coming out of it usually with a plug with 3 terminals, if so you can pick up a Tach signal here, as it is plus, minus and signal, mercury/Mariner tachs work from here. If you buy one from ebay it needs to be for boats with a 2 stroke engine, Faria are a cheaper alternative to OEM.

 

[Mavric]

Do you have a control box (throttle) with a short lead coming out of it usually with a plug with 3 terminals, if so you can pick up a Tach signal here, as it is plus, minus and signal, mercury/Mariner tachs work from here. If you buy one from ebay it needs to be for boats with a 2 stroke engine, Faria are a cheaper alternative to OEM.

Hi and thanks both for the reply it's a faria tach gauge and came with the boat i cant seem to add photos of it on here their too large  anyway there are 3 wires coming out of my throttle control my not colour coded as i think the previous owner of the throttle control changed them , i also want to add a temp gauge to my outboard will an automotive one for bikes cars and boats do i don't think ive got a spare hole on my block but been told to use a sensor that i attach with a z bracket so it's touching the block but can't find a sensor or z bracket ???? if either of you email me ill send a couple of pics of my tach gauge for you too see it email mondeost22@yahoo.com cheers steve.

 

[Mavric]

Hi and thanks both for the reply it's a faria tach gauge and came with the boat i cant seem to add photos of it on here their too large  anyway there are 3 wires coming out of my throttle control my not colour coded as i think the previous owner of the throttle control changed them , i also want to add a temp gauge to my outboard will an automotive one for bikes cars and boats do i don't think ive got a spare hole on my block but been told to use a sensor that i attach with a z bracket so it's touching the block but can't find a sensor or z bracket ???? if either of you email me ill send a couple of pics of my tach gauge for you too see it email mondeost22@yahoo.com cheers steve.

Ive sorted the tach out now but i have another problem now i was running my outboard on muffs after the winter and i was
trying the steering but everytime i steer left or right it cuts out if it's not running and i steer left or right it blows the main 20amp fuse under the cowling it didn't do it before ????

 

[spannerman]

Either something is rubbing on the main harness and shorting out the 12v feed up to the control box, or something under the cowl is doing the same thing, check when you turn the steering that the harness where it goes into the cowl isn't being trapped causing a short, it will probably be between the main fuse and where the harness goes into the boat as all the rest is stationary.

 

[Mavric]

It only dose it when turn the steering mate so i was thinking where it goes into the engine too but can't see anything maybe a couple of wires have got snagged and earthing out cause a short within the loom under the cowling it's not the throttle controller end as that cable dosent move .

All sorted turned out it was the part of the loom just before it goes under the cowling 4 wires had their rubber coating come off and they were arcing against each other so pealed it back and fixed it �� , wired up my speedo and tach and they light up too �� , haven't tried it yet as too late but when i turn key to position 1 both clocks light up , my question is will the tach needle only move when the engine is started or should it move when i turn ignition to position 1 ? .