1gm10 tachometer not working

[sailorbaz]

I had to motor to the yard for anti fouling this weekend. When it started the buzzer continued to sound and the rev counter wasn’t working. There was plenty of water coming out of the exhaust. The warning lights haven’t worked for a long time and it’s difficult for me as an old bloke to climb in the lazarette to get behind the panel. I switched the buzzer off and motored down to the yard - about 20 minutes. The motor wasn’t very hot. Does anyone have an idea as to which sensors I should look at and what does the rev counter connect to.
TIA

 

[Dellquay13]

I’d check the alternator and wiring first, if the buzzer stays on after a few seconds after starting. Get a test meter on the charging circuit (or battery) to see if it’s working at about 13.4v or more after a few seconds at a bit above tickover.
The tachometer is an optional extra on the basic 1gm10 (I don’t have a tachometer on mine) but again points to the alternator as a first check.

 

[Martin&Rene]

I think the 1gm is like the 2gm in that the tachometer runs from a (Hall?) sensor looking at the flywheel and not from the alternator. Check the contacts are clean.

Re the buzzer, see if this makes a difference. A good simple check is to just hold the key in the start position for a few seconds after start up.

 

[Dellquay13]

I think the 1gm is like the 2gm in that the tachometer runs from a (Hall?) sensor looking at the flywheel and not from the alternator.

The base 1gm10 doesn’t come fitted with a tachometer, just a basic panel of key, start switch, overheat buzzer /lamp, no charge buzzer /lamp.

The normal running temperature and immediate Buzzer continuing from startup points this to being the alternator warning buzzer, not the overheat buzzer.