Yanmar tachometers "calibration"

[DeniseO30]

On my 3gm30 I have of course the flywheel mounted sensor for the tach I'm quite convinced it's is off by maybe 300 RPM at higher RPMs low RPM seems okay (no I don't have a handheld tach, ) seems to me the sensor could be cleaned but from the little bit of research I've done, it's usually the tachometer itself needs to be replaced? Not something to do today, but put it on the to-do list for the future!

 

[kloudie1]

Not unusual .. mine is off 400-500 RPM.. I think when I do replace it, it will be with a VDO .. some of their diesel tachs can take input from our "tooth counter" pickup .. I had decided on their model 333-163.. but it looks like no one has those.. chip shortage maybe?

 

[Ralph Johnstone]

A new tach is not a big deal. VDO is the best buy.

Could It Be The Tach Sensor??

My tach has never worked correctly in the eleven years I've owned my boat. Steadily it's been getting worse. The engine is a 1983 Yanmar 3GMF. When I first bought the boat the tach reading on the engine panel maxed out at 2200 RPM's. Today it only registers about 1600-1700 RPM's when the engine...

forums.sailboatowners.com

It's also a good idea to invest in an optical tach. Any VDO can be setup without a tach but it's always nice to run a check every few years. You want the cheapest handheld tach you can find with no bells and whistles. This is identical to the one I bought about twenty years ago and paid about four time as much.

Crazy Sales Digital Tachometer, DT2234C+ NonContact Digital LCD Photo Tachometer Mini RPM Tester Meter : Amazon.ca: Industrial & Scientific

Crazy Sales Digital Tachometer, DT2234C+ NonContact Digital LCD Photo Tachometer Mini RPM Tester Meter : Amazon.ca: Industrial & Scientific

www.amazon.ca

I'd suggest getting the optical tach first and checking your currently installed tachometer.

 

[senang]

There is also Tinytach as a digital rpm & eng hours solution. The sensor is placed on the injection tube for measuring pulses.