2002 90HP... Last week first thing in the morning started to run WOT and the overheat alarm came on. Shut it down, alarm went off. When I re-started it the alarm did not come on, but the motor could not get on plane, started vibrating when I tried to go faster. Shut it down again, turned it on and it idled just fine. Fished for 45 mins and it ran fine after that. I don't think I went WOT, but got on plane heading towards ramp with no issues. Water was peeing the whole time, and impeller was replaced in 2022.

I wasn't around any sand or vegetation. Straight from ramp out into the middle of the lake. I also let motor run when tied to the dock while I parked my truck to warm up. I did throw boat in reverse before putting it on the trailer incase something was in the prop, but like I said it ran normal when heading back to the ramp.

Any ideas what caused the alarm to go off or vibration when trying to get on plane and what I should replace? New Thermostat or something totally different?