Tach not working on my 2GM (Catalina 30 repowered with this 25 years ago). According to PO, it went from good to reading 1/2 of tach then a few years later nothing. Is the tach driven from magnets on the flywheel (would make sense to me) or off the alternator?
tach with Yanmar 2GM not working
- Thread starter lunasea6
- Start date
-
- Tags
- tach yanmar
Not sure if it's magnets but the signal does come from the flywheel with the factory installation.
Tachometer Sender Testing.pdf
Probably easier to get a new tach. Got an electronic VDO several years ago and never looked back. About $100.00.
Thanks, probably not going to get new magnets stuck on the flywheel so a new tach is in order then.
I posted the shop manual in the engine forum. There is a chapter that covers the electrical and shows the sending unit located on the bellhousing. Mine stopped working on my trip last week. Pulled the two connectors on the sender and cleaned with a piece of sandpaper then greased. Works again.
There are no magnets on the flywheel. The sender senses the passing of the teeth on the starter ring gear to detect engine speed.
Cleaning up and reseating the contacts has a good chance of success. Do the same at the panel end.
If you end up replacing the instrument you will need to know the number of teeth on the ring gear to set the calibration
Cleaning up and reseating the contacts has a good chance of success. Do the same at the panel end.
If you end up replacing the instrument you will need to know the number of teeth on the ring gear to set the calibration