1988 454 Mag Dies
 

Hello I am new to this but I have a 1988 Checkmate Vision with a 454 Mag. I am having an odd problem... I put the boat in the water and after running for 10-15 minutes she dies. She will start right up but then almost immediately start running rough and then dying out. He is the odd thing, when I start it and it's running rough if I hit the trim switch it fires right back up like nothing is wrong. Then If let go of the trim switch it dies again. Definitely electrical and I have checked every wire twice but can't figure it out. So frustrating!! It will run like nothing is wrong in spurts but eventually dies out unless I hold the trim switch. Very odd, any help would be GREATLY appreciated!

I would do a voltage drop test on the ground wires, or remove them and clean as needed. Sounds like a ground issue?

did you ever find out what your issue was ? mine would die above 4000 rpm's. turns out I had a short in the alternator, put a new alternator on and seems to run fine now. what get's me is I don't know why the breaker on the motor didn't pop. it would die just like you turned the key off and then restart. dave