Tachometer Problem

[Graceland]

Question for the group here. I have a 25 CC with a 315 Yanmar. As of late my tachometer has started acting up. It works for 5 or 10 minutes after starting the boat up and then it drifts away to 0 and doesn;t work for the rest of the day. Any suggestions on where to look? I have checked the battery connections and the altenator seems to be charging correctly. I have also checked all the wiring on the back of the tachometer and on the altenator. Any ideas would be greatly appreciated.

[sunshineva]

Darran,

I had an almost similar problem with one of my tachs on volvo diesel engines. CC28 with KAD300.

It turned out to be 1 loose ground on the starboard engine.

Worth checking!
sunny

[NORM]

HI DARRAN
WE HAVE A 2000 C.C. WITH THE 300 HP YANMAR, OUR TACH WILL NOT WORK RIGHT AFTER I WASH THE ENGINE... THERE IS A GROUND ON THE LEFT SIDE OF THE ENGINE UNDER THE INTAKE MANAFOLD, THIS HAS SOMTHING TO DO WITH THE TACH. WE ARE SELLING OUR 2000 & MAC IS BULIDING A 2006 WITH THE INBOARD & A 315 YANMAR !!!!!
DO YOU KNOW OR HAVE SEEN ANY 25'C.C. WITH THE INBOARD ???
LET ME KNOW IF I CAN HELP YOU ANY TIME + I PUT UP A POST ABOUT A BONE HEAD MECHANIC !!

NORM

[Graceland]

Norm,
I think you diagnosed it. I installed a Groco 3 way right where you are talking about and have seen that wire. I use the 3 way to hook air into and blow out my sea water side in the winter so she doesn't freeze up. That wire is right below the plug and has a but connector. I fiddled with it a while back trying to move it from undernaeth the Groco so it wouldn't get wetted when I pulled the plug. Now that I think about it, that's when my tach started working for a few trips. I'll take a look at it tonight. Keep your fingers crossed.

[rcasper]

rcasper

HI I have a 2000 28cc with 300 yanmars my tacks are doing the same. I am getting ready to replace the tack. I will check the connections and grounds again. I just thought with so many of us having this problem it would be a easy one to correct but then again its a boat. I let everyone know if I get a fix.