Rev counter on Yanmar 2gm20

[DavidGrieves]

Hi all

Trying to help a friend out, he has a Yanmar 2gm20 and he wants to fit a rev counter. He has got hold of a rev counter from a Volvo Penta MD11c, but when ive looked at the engine there isn't a pick up/sender for the rev counter, just a blanking plug on the bell housing.

Question is where can we get the pick up from?

Or could this type of rev counter be made to run of the "W" connection on the alternator. (i'd have to solder a wire to one of the AC field windings to make a W connection).

Thanks

 

[VicS]

Hi all

Trying to help a friend out, he has a Yanmar 2gm20 and he wants to fit a rev counter. He has got hold of a rev counter from a Volvo Penta MD11c, but when ive looked at the engine there isn't a pick up/sender for the rev counter, just a blanking plug on the bell housing.

Question is where can we get the pick up from?

Or could this type of rev counter be made to run of the "W" connection on the alternator. (i'd have to solder a wire to one of the AC field windings to make a W connection).

Thanks

Id expect to be able to get a Yanmar pick up coil from a Yanmar agent but it might cost many beer tokens. Even then the tach from an MD11C may not be compatible.

A simple solution might be to buy a "TinyTach" http://www.tinytachuk.com/diesel.php

 

[earlybird]

As VicS says, the Yanmar pick up is pricey. I costed one some years ago and it was £100+ IIRC.
It counts gear teeth, as does the Volvo equivalent AFAIK, and which is even dearer, so you may well have calibration problems even if it reacted to the signal.
Ditto if adding a "W" terminal.
Ebay sell tachos intended for W terminal drive for £50-£60;- a possibility?

 

[Billjratt]

Well the first question is about the tacho head. Is it looking for a "W" signal (easy) or has it terminals for a sender signal?
I would go for the "W" solution, as you've already indicated you can solder a wire to the alternator coil if there isn't already a terminal available - even if it means looking for another tacho head. Engine senders can be notoriously expensive and then you've got to know the tacho is compatible.
I've seen a VP head with a calibration pot behind a plastic plug on the side and terminals for "W" and "G" as well as + & -, so it can maybe be used for either/all inputs.