Thanks everyone for the suggestions. I will look for blockage and cavitation issues.
The pump is direct controlled by a gear
on the shaft which mates with a gear
in the engine
. I don't think it is an alignment issue because the seals
is a right hand rotation.
I have pulled the heat exchanger
and it is clear. The exhaust elbow
is new. I might just replace all the raw water
hose in case the inside wall is delaminated and caving. The run from the thruhull to strainer to pump is <3'. The run to the antisiphon valve is 3' and the run from there to the engine is 2'. So the hose runs are short and straight.
The flow rate is more difficult to check because the outlet is very close to the waterline. Just by eyeball, the two engines appear to be spitting out the same amount of water
. When an impeller rips, the change in water
output between the two is noticeable.
What would be the signs of cavitation inside the pump housing?