Yanmar 2qm15 Tach

[Dallas Malloy]

I recently purchased a '78 33 with a yanmar 2qm15 engine. Through discussions with the previous owner, I determined that the tachometer was unhooked by a shop during engine work(don't ask me why). I have also been able to gleen from the owner's manual that the tach sending wires are orange and blue and have located these hanging from the wiring harness at the engine. I assume that the tach was reading from the alternator since I cannot locate a sending unit. Any information regarding the wiring/connection of the tach to the alternator or sending unit will be greatly appreciated.

 

[Dallas Malloy]

Nice plug there

I looked there Carl. I see a plug where I assume a sending unit would go. I believe that there are two ways to provide signal to the tach. One is via sending unit and the other is via sigal from the alternator. Unfortunately all the yanmar manual says about the subject is "optional".

 

[Dallas Malloy]

I'll Do that

Thanks Carl...

 

[Dallas Malloy]

Yes John

...I would like to know how. I just spoke with my local yanmar shop and found out the sender is obsolete and not available.

 

[John Tesoriero]

Tach calibration

Tachometer Timing: Place strip of white tape near outer edge of the face of the flywheel pulley. Shine a shore powered (60 cycle AC) fluorescent lamp on the pulley with engine running. At 1,800 RPM you should see four steady, stable tape marks hovering at 90 degrees from each other. Adjust your Tach. If you can get up to 3,600 RPM there will be two steady marks hovering at 180 degrees from each other.