Tachometer issue

[fisherofmen]

I have a 2004 YANMAR 6LPA-STP. The tachometer recently started acting up. It is fine when I start and get out of the harbor. After about 10-15 minutes it slows down about 1000 rpms. Shortly after that it goes down to 0. The engine runs fine and keeps the speed but the tach doesn't register.
Any ideas? Thanks JP

[REBMystic]

I had some issues and luckily was just a loose electrical connection on the sensor. Stbd aft end of my 6lp-ste

[fisherofmen]

Thanks, I'll check that.

[fisherofmen]

Thanks for the info on the tach sensor. I cleaned the terminals and it worked all day. One of the easiest fixes I've encountered so far.
blessings.

[REBMystic]

Ahh. That's great! Yea, we gotta take those wins when we can!

[markd43]

I’m having the same problem on my 2003 6PLA-STP any pictures on what the unit looks like and where it’s located would be helpful. I did try shining up all the wires behind gage at panel, didn’t work.

[REBMystic]

PXL_20250727_163722951.jpg

PXL_20250727_163735847.MP.jpg

Here is the sensor. Back on the transmission. Stbd side.