Yamaha 4.3 trim gauge flashing and reduced power when turning right

[Jklumpp]

I'm new to this forum but have been teadinv as a guest over the past few years. I have a 93 regal valanti with Yamaha yems 4.3 sterndrive. This past summer the boat started slowing to 2400 rpm whenever steering wheel is turned at all right of center. At the same time the trim gauge will flash indicating leg is fully up even though it is not. My question is does anyone know if these engines are equipped with a safety slow the engine down if trim is up. I'm wondering if I have a trim sender wiring issue that could also cause the engine to slow down. Every time it happens, the problem remains until engine is turned off and then restarted. Then all good until turn right at all. Any ideas would be appreciated

 

[Bondo]

Ayuh,..... Welcome Aboard,..... That's certainly an odd problem,....

I guess I'd crawl around the bilge, 'n see if there's interference between the steerin' linkages, 'n any wirin',.....

I don't know much about Yamaha's,.... they were only imported a year or two,.....

 

[Jklumpp]

Yesterday I removed the brackets that hold the trim sender wires outside the transom. Just by wiggling I can get the trim gauge to read full up and start flashing. Also after looking at the terrible wiring diagram in my manual it does look like the trim sender wires are connected to ignition circuit wires. I'm now partway through pulling the pivot housing for access. Also going to repair broken speedo tube while I'm in there. All wires on the inside seem fine and are not catching or rubbing as far as I can tell. I'll install a new trim sender and go from there. I suspect it will fix my problem.

 

[QBhoy]

Wish you all the best. But an out the box thought and presumption is that this engie in your regal of that age likely means it’s been re engines at some point. Was the drive changed too ? This could point at a few things being off maybe ?

Drive position and set up when installed
new engine mated to older ancillary things and or controls and gauges.

Just a thought. Might be way off ?

 

[Capt Ken]

Your sender is shorting causing the ECM to think the drive is too high and yes it goes into rpm reduction and the trim gauge will flash. Yamaha drives were installed in boats through 1995. Boats builders warehoused them and used them for years after production stopped.

 

[QBhoy]

Good info. Just thought it unlikely an option on this boat. Yamaha drives are fitted on boats local to me even only a few years ago. Usually on Diesel engines though. Occasionaly a Yamaha labelled GM4.3 too.