Omc cobra 3.0 impeller ???

[Ole walk walk]

This boat is giving me headaches!!! Ugh. I just recently replaced the impeller and thermostat. Boat ran fine then began to overhear again. Today I pulled the impeller back out and checked it. One of the fins was ripped 3/4 of the way. Could that one rip cause the boat to overheat? If so is there anyway to make sure the next one last longer than 10 hours? Btw I replaced the housing and all the gaskets as well. Thanks in advance!

 

[cr2k]

Re: Omc cobra 3.0 impeller ???

Did you seal the gaskets behind the wear plate? Is the cup turned in the housing? is there any signs of melted plastic in the housing? Is the "O-Ring" housing gasket glued in to the groove? Did you lube the impeller when you put it in? Any of these things (and a few more) can cause problems with a cobra pump.

 

[jerryjerry05]

Re: Omc cobra 3.0 impeller ???

You starting it without water?
Replace the wear plate?
If you start a drive/motor without water for even a few seconds it can do damage.
And yes 1 bad vane can cause your problem.
Like CR2K suggested,grease on the vanes when assembly.

 

[Ole walk walk]

Re: Omc cobra 3.0 impeller ???

No, I've never started without water. I did replace everything the first time but did not "grease". I did put a lubricant on it. I will replace the impeller again and grease properly. Thanks for the help. Just wanted to know if the one vein would cause the engine to overheat. Another ??? As long as the water pump motor is turning its working? How can I test it if this is not the case. Don't know how to other than turning the engine over to check for movement. Thanks again for the help.

 

[Howard Sterndrive]

Re: Omc cobra 3.0 impeller ???

can probably just grab the alternator belt and turn the engine by hand enough while someone else watches the impeller

 

[sea wolf]

Re: Omc cobra 3.0 impeller ???

No, I've never started without water. I did replace everything the first time but did not "grease". I did put a lubricant on it. I will replace the impeller again and grease properly. Thanks for the help. Just wanted to know if the one vein would cause the engine to overheat. Another ??? As long as the water pump motor is turning its working? How can I test it if this is not the case. Don't know how to other than turning the engine over to check for movement. Thanks again for the help.

You don't need to grease it. Just a few drops of 90w oil will work just fine.