62 Lark 40hp water pump problem

[mstahl1171]

I had to rebuild the lower unit and installed a new water pump impeller and seals. Motor ran fine yesterday and pumped water. Today no water pumped at all. dropped lower unit and check the pump, made sure impeller is installed correctly, verified impeller key is installed. All looks fine. I also checked the copper tubes and seals. Removed the thermostat and boiled in a pot of water to confirm operation. Is there an easy way to test for a blockage in the powerhead? Could the impeller be bad even though it is new?

PS...I removed the thermostat and tried running the motor at the ramp..still did not pump.

 

[tx1961whaler]

Re: 62 Lark 40hp water pump problem

You can try running it at home for a minute with the thermostat and thermostat cover off. If the pump is not working up to there then the problem is in the pump.

 

[mstahl1171]

Re: 62 Lark 40hp water pump problem

Thanks...I'll try now before it gets dark and post details

 

[mstahl1171]

Re: 62 Lark 40hp water pump problem

I tried the thermo cover off and no luck...so I dropped the L/U for the third time and put the old impeller back in...works like a champ. Found the new impeller has a spun brass hub. Never seen that before...so I'll order go get another one. Thanks for the help tx1961whaler!!