Yamaha Fuel Mgmt Sys is POSESSED! - The Hull Truth

Fcal · 09-23-2007, 03:49 PM

Already went over this with SIM. Starboard reading went out about 3 weeks ago. After playing with the connectors, swaping etc. I came to the conclusion that the starboard sending unit was bad. Well $289 later I replaced the sensor and it worked during a whole 8hr fishing trip. Went fishing 3 days later, no starboard reading again. Did the same diagnostics and came to the same conclusion. Sending Unit......... Dealer convinced me to try a new harness. Ran the harness over the deck first. It worked again. Got the P & S reading for both motors. Now it gets good...............Went fishing the very next day. NO Starboard reading WTF! It worked intermittently while I was running.
Dealer is giving me another sending unit on Tues.
Anyone have any similar issues with the FMS only reading one motor?

salty_dog · 09-24-2007, 10:00 AM

I am having the same problem with my starboard motor. Going into the dealer on Thursday to have them take a look. I checked all connections, they look fine, and swapped out motors. It is also my starboard sending unit. Not holding out much hope, the dealers said they didn't have many problems with these units.

Fcal · 09-24-2007, 06:00 PM

Salty, I sent you a PM. The dealer told me that he just replaced three of these in the last two weeks.

A Frayed Knot · 09-26-2007, 05:42 PM

Verify that the connection from your tachometer is not loose, common in the quick connection Yamaha uses in their wiring harnesses.

If your fuel management gauge doesn't recognize RPM it can cause intermittent reporting of fuel consumption

If it's the starboard engine fuel consumpation giving you problems check the green wire connection coming into the fuel managment gauge

Fcal · 09-27-2007, 08:42 PM

I replaced the sensor a second time (free of charge) and it's working again. It's not the tach connection because I have no problem with the SYNC function. The gauge is recognizing both motors. I think I just had a bad replacement part. I'm thinking Yam might have had a bad batch.

bens2 · 09-27-2007, 11:24 PM

This is all very interesting. I have twin F250s and my command link gauges have been acting up for a month now. I will intermittently lose the starboard tach, fuel management, speed and have lost the port tach.

My local dealer couldn't fix it and Yamaha was called in. Their rep said he fixed it but I took my boat out today and starboard tach went out again.