Motor runs fine, starts fine, but realized voltage is not where it used to be. Use to run in the 14 range but now high 12 or low 13 on sonar unit. Tach is about 1000 rpm higher at high rpm.

Any ideas? Where to start.

Links, ohm checks, or photos appreciated.

John

Minr did that same thing and it wound up being dirty connections at the battery. Took them off and cleaned then up and voltage came back up to 14 volts.. Hope this helps!!!

TTT and thanks for the advice Duane...

Your Welcome!!!!

Went to the old battery and at rest was reading 12.1 and with the motor running it was 13.2 - 13.4 .

I bought a new battery last night so I will see what it is after installing the new one.

What puzzles me is I see that my volt meter is reading a little lower than normal. Used to be around 14 where now its dead on 13 and when you push down on trim switch it
drops to 11.

Next thing is the Tach. Was reading
perfectly and now it runs fine but what was 5400 now reads a little over 6000. I know this is not a real reading.

Just ordered service manual so hopefully it will have some troubleshooting ideas.

Would like to hear how this goes. I had a recent issue with my 250 hpdi. Put in a new battery and so far 2 trips and all is good so far...

Good luck!

Well here is what I have so far....

THE OLD BATTERY:

At rest this battery was reading 12.1 volts. With the motor running the old battery was showing 13.1 volts. When you would hit the trim or tilt switch it would knock the battery down to 11.2 to 11.5 volts. It would regain (SLOWLY) back to 13.1 volts. Gauge on the console just dead on 13 volts.

THE NEW BATTERY:

At rest this battery was reading 12.45 volts. When I fired the motor up it instantly went to 13.8 - 13.9 volts. Gauge on dash was reading over 13 where it normally ran. When you would hit the trim and tilt switch voltage would drop down to 13.2 and instantly just back up to 13.8

I will be running the boat this weekend so I will know more but so far it is in better shape then it was early in the week.

New battery did not fix the problem. Voltage was definately reading higher then with old battery but at low rpm voltage still dwindling around 12.5

At higher rpm 1500 or more voltage increases from 13.5 to 14

Also Tach still at WOT reads 6400 RPM. At idle and up to about 3000 RPM Tach is fine then it just races up to 6400.

Motor still runs fine and sounds the same as it always does.

Checked all grounds everything tight no burnt wires. The stator did not appear to have any burnt spots. I Just got the manual so plan on doing some tests soon.

Anyone with similar issues?

Have you had it hooked up to a computer yet? I'd consider taking it to a shop and letting them at least run a diagnostic with the yamaha software. Worst case scenirio they charge you an hour of labor. Might save you lots of time and give you a better idea of where to start if you want to tackle the job yourself. My voltage issue seemed to be solved with a new battery, but I was also having far different symptoms then what you're having. Check my recent post in this section if you want to hear more about it. Good luck and keep us posted.

Brazos Bass Cat thanks for the advice. I plan on doing that...