Ghosts in the machine
 

I bought a new Fountain 38 EC with 496 HO's last October. It has ran flawlesslessly since its inception. Last month I pulled it out of the bay and trailered it to the Boyne Thunder Poker Run, and as soon as I got it in Lake Charlevioux the port Tach ran noticibly faster than the stbd. Example; with engines synched at about 4000 rpm, the port was showing about 4500 rpm. When I returned home we put the scanner on both engines: no errors recorded, and the computer confirmed that the port tach was running high, and it got proportionally worse as the rpms increased. Shogren overnighted me a new tach, and the problem was slightly worse using the new tach.
Help!
Carder

help, please?

Is the battery voltage ok on the port motor? When the voltage drops on my starboard motor (from running the stereo) my tach jumps around and shows higher rpm untill battery recharges.

Steve

I'll check it tomorrow. Thanks for the tip!
Carder

Run the scan tool on the engines when running at 4000 to 4500 rpms and see if the problem is in the engines or in your wiring or tachs.

Best Regards,
Ray @ Raylar

Thanks for the input Ray!
Computer showed the port tach increasingly higher vs what the computer was reading through the whole rpm range. As you know, revlimiter is at about 5100 rpm, tach was showing around 5400 without warning lights/horns. As soon as it got over 5150 rpm on the computer the rev limiter kicked in.
I will have him repeat as you suggest at 4000 to 4500 rpm.
Carder