Fitting an engine hour meter (advice)?

RobWales

RobWales

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Joined
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www.3ksengineering.com
Hi All,

Recently bought a 24' cruiser which has had a brand new 4.3MPI engine fitted due to frost damage on the original motor.
With the engine having run less than 20hrs from installation I feel now is an ideal time to fit an hours run meter as the boat does not have one fitted as standard.
However where would I take the positive supply from? not sure I want it from the ignition as ignition may be switched on but engine not running....hence false hours reading....so where would I get a supply that only supplies when the engine is actually running?
Alternator perhaps?
Thanks, Rob.
 
On my 2GM10, I put it on the ignition on the grounds that if the ignition is on and the engine not running, you have an alarm shrieking at you so you turn the ignition off pretty quick. The difference between actual and recorded time will therefore be very small. If you are concerned about minute errors, one of the terminals on the alternator will work. This would have made the wiring a bit more complex for me.
 
ghostlymoron said:
On my 2GM10, I put it on the ignition on the grounds that if the ignition is on and the engine not running, you have an alarm shrieking at you so you turn the ignition off pretty quick. The difference between actual and recorded time will therefore be very small. If you are concerned about minute errors, one of the terminals on the alternator will work. This would have made the wiring a bit more complex for me.
Click to expand...
I agree, the total time of ignition on but engine not running is usually quite small. Mine is setup as above.
I used a cheap electro mechanical counter from Maplin or RS (can't quite remember)
 
Mercruiser ignition, off, on with one beep then turn again to start, however can turn back to pos one with no alarms.....ok so motor stops but ignition can be left on unnoticed I would think.
 
Last edited:
RobWales said:
Hi All,

Recently bought a 24' cruiser which has had a brand new 4.3MPI engine fitted due to frost damage on the original motor.
With the engine having run less than 20hrs from installation I feel now is an ideal time to fit an hours run meter as the boat does not have one fitted as standard.
However where would I take the positive supply from? not sure I want it from the ignition as ignition may be switched on but engine not running....hence false hours reading....so where would I get a supply that only supplies when the engine is actually running?
Alternator perhaps?
Thanks, Rob.
Click to expand...

I have a raw water flow switch that when water is flowing connects a light to the 12vdc negative so I connected to positive of the hour meter to the output of the ignition switch and the negative to the switched side of the raw water switch so the hour meter only runs when the engine is running with raw water flowing.

Its also possible to do this with an oil pressure switch.
 
Hi,

Think it through and take your time.

I have a Volvo. Ignition can be on without the engine running but with no alarms.
Fine, I thought, connect the hour meter across the ignition switch. I will never leave the ignition on without the engine running.

Three years later, boat in a hot climate, when 'finished with engine' ignition stays on for at least half an hour because that runs the engine room fans and cools things down a bit.

Must get around to changing it but in 35 to 40 temps, it's a hard job!!

Tony
 
In the 1980's you could buy an engine hour meter which worked off vibration, you bolted it to somewhere on the engine (a cylinder head bolt is ideal) and whenever the engine was running the hours would be recorded. I managed to buy another one off the internet recently. Certainly better than messing about with wiring.
 
My Lancing XLD has the engine hours run off the engine run relay, which has power to it to run, and stops when power removed. The OP's sounds like petrol, so hrs meter could run off the Ignition "on" position
 
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