Just had a lower unit rebuild recently, motor ran fine for a 1/2 day after rebuilding. Then it started overheating. I noticed I had good water and good psi at idle. But as soon as the bow breaks over on holeshot my water psi drops to zero water stop coming out of the engine, and overheat alarm sounds shortly after.

I would think that if I'm getting good psi at idle that the pump is good.

Any ideas?