1999 5hp Johnson not pumping water

[gerrybc70]

I recently bought a 1999 5hp outboard (5REEC) and found that it would not pump water. I replaced the impeller and it still will not pump water. The water pump its self shows little or no ware. I have cannected a drill motor to the shaft and submerged the pump in water and it appears to pump plenty of water with sufficient pressure. If I leave the rubber grommet out of the shaft housing the water seems to flow normally. Is it possible that the exhaust pressure over riding the water pump pressure? If so what is the fix?

[Daviet]

It's possiable for the head gasket to be defective and allowing exhaust into the cooling system and causing it to overheat.
I would drop the lower unit and attach a water hose the the water tube and check the engine for water flow. You could have a grommet at the top of the water tube damaged and not allowing water into the block.

[gerrybc70]

1999 5hp Johnson not pumping water

Davit,

First thanks for the advice.

I removed the lower unit and connected a hose to the water supply tube. Turned on the water and most of the water exited via the shaft housing with a little coming out of the "pee" hole. Does that mean that I have a leak between the cooling water into the exhaust system and or the rubber grommet is bad at the top of the water supply tube?

[gerrybc70]

Davit,

First thanks for the advice.

I removed the lower unit and connected a hose to the water supply tube. Turned on the water and most of the water exited via the shaft housing with a little coming out of the "pee" hole. Does that mean that I have a leak between the cooling water into the exhaust system and or the rubber grommet is bad at the top of the water supply tube?

[Daviet]

The water will come out of the exhaust housing, that's how it gets out of the engine.
How were you running the engine, in the water or in a barrel? If in a barrel, did you have the water level above the water pump?

[gerrybc70]

It was in a barrel and the water level was above the water intake.

[Daviet]

The water level was above the water intake, but was it above the water pump. If the water pump is higher than the water level you will probably overheat. The water pump will pump water very well, but it will not suck water worth a darn.
You need to make sure the water level is above the pump by 4-6 inches when running in a barrel.

[gerrybc70]

Thanks again I'll try it and see. I was an easy 3 inches above the water intake but not 4 to 6 inches above the level of the water pump.