Yanmar 3YM30 Tach Lead Optical or Lead off Alternator

[mytime]

We purchased a 2007 Hunter 33 without a working hour meter. The previous owner kept excellent maintenance records and it seems the tach digital hourmeter has failed twice. I would like to replace it with a analog hourmeter on tach instead of a digital one. I have not been able to go through all the systems yet. Does anyone know if it has a optical pick up or a lead off the alternator to send signal to tach...It has the 60 amp Alternator...Thanks

 

[Ralph Johnstone]

Do not confuse boats with cars. Your tack is whatever Hunter chose to put in there at the time. Maybe two different makes of tack in the same year.

Ignore the original tack and get the tack you want with an hour-meter. Modern electronic tacks will take an input from anything that moves.

I replaced the original tack (no name brand or at least none recognizable) with a VDO 333-163 because it had the same hole size and matched the appearance of the rest of the gauges. Used the flywheel pickup for the RPM sensing and an optical tack for the final calibration. Could have done the final calibration by calculation but had the optical tack around. Has behaved perfectly for the last ten years.

 

[mytime]

Thanks Ralph!...I was looking at another Marine Tach and the diameter seems to be the same. It has the option for either model optical or Alt sensing. I just prefer Alt sensing if it was wired for it

 

[jssailem]

tack you want with an hour-meter.

Or get a Tack and a separate hour meter.

The hour meter can be a simple electrical connection that runs when you turn on the engine and shuts down. It can be analog like a Hobbs Meter with rotating dials that move or stop. Not relying on electronics to provide a continual recode of time running. Only need to assure that the electrical connection it good, like all electrical connections on a boat - they corrode.

 

[karellen]

Or get a Tack and a separate hour meter.

That was the route I took on my 356, which didn't even come from Hunter with an hour meter. I just left the original Yanmar tach in place and stuck this inexpensive hour meter in the engine bay.

 

[jssailem]

@karellen I was in the same boat sort of. The boat had no indicator of how long the motor had been run. So I got a Hobbs Meter and instantly the issue was solved. Wired it to the engine on switch and when the engine runs the clock runs. It is now a whole lot easier to time the need for filter changes, fuel consumption, impeller replacement. Maintenance has gotten a whole lot easier.