2001 Yamaha F100 Four Stroke

Headed out fishing this past Memorial day weekend in Morehead, NC. Launched boat started it to let idle and warm-up for a few while I parked the trailer. When I came back it had stalled/ was not running. Did not think much of it, Turned the key started right up. We headed out, got about 4 miles to a no wake zone so we came down to idle. After a few minutes she stalled again. This time no starter crank, no trim and I smell burning plastic smell. I disconnected power with cut-off switch and checked the battery as it was new. Everything looked fine and everything else on the boat powered up fine and read 12.4 volts. Popped the cowling cover and definitely smell was coming from the motor.

With Sea Tow looming, I gladly fired up my F4 Yamaha kicker and got us back to the ramp safely. Fishing of coarse along the way. Back at the ramp I was able to quickly determine that one of the 30amp ATM fuses was blown that corresponds to the tilt/trim and starter. I jumped the fuse to get the motor up and boat back on the trailer.

The local ACE hardware had new fuses to replace the dead one. However, the motor is now very rough, starts intermittently usually after sitting a while. Tilt and trim seem to work fine but I am beginning to think I have a combo gas/electric problem causing my issues.

My first stop will be to clean the carbs, change the fuel filter and fuel lines.
Electric wise, I am thinking of checking the T/T switch and T/T motor for corrosion, shorts etc.

Any additional thoughts or leads would be appreciated.

Thanks, M.

You might look at the regulator rectifier and connector for signs/smell of a problem..

I am also looking at the tilt trim and starter relays. The 30amp fuse that was blown goes directly through these relays.

Changed fuel filter, lines and cleaned carbs. Rebuild ptt motor. Found the back of the Regulator Rectifier completely burnt and melted. Thanks PBRMAN for the lead! Replacing R/R and starter relay.