water pump problem

[Brick]

Bought a used lower unit for a 1988 Suzuki 115 HP. Put a new impeller in the water pump. With RPM between 700 to about 2500 the pee hole was putting out a good pressure. When I increased the RPM >2500 the pee hole went to 0 discharge. When I slowed the motor down to idle, the pressure return. Any ideas????

 

[jl_photo]

Re: water pump problem

are you sure the key is in place? the impeller could be spinning at times. not likely but possible. are you sure you have the right impeller?

the impeller works as a collapsing vane pump at lower rpm and then acts as a centrifugal pump at high rpms. the pump may have more presure and suction at lower rpm. if there is some kind of restriction on the intake or output this could explain your symptom.

also try testing the engine at high rpm in neutral.