Sand in motor?

[trip29]

I have a Yamaha 115 v4, 1987. I was in shallow water and stirred up sand. The motor ran great all day. I took it out a few days later and it ran great for 3 hrs, stop n start fishing and at full throttle for a considerable distance. As I was returning we hit a few lg swells and bounced a bit. The engine made a grinding sound and shut off. It wouldn't immediately restart, but after a few mins i got it running. We were able to limp back to dock at less than 2000 rpm. If i tried to go any faster she would lose rpm and shut off.

overheating? sand in cooling sys? what do you think?

Thanks......Trip

[boats.net]

If it's overheating the alarm should sound the buzzer(as long as buzzer is working properly). Probably should check compression, test alarm buzzer and check engine to see if is overheating.