shreded a brand new impeller....why?

stevo10081984

Seaman Apprentice
Joined
Jan 16, 2011
Messages
40
hey guys, i replaced my whole water pump in my 1988 28hp johnson about 2 months ago.....i ran it in a barrel it worked great....i wanted to have it ready for summer, so after that i replaced the thermostat...after replacing the thermostat i ran it again...the water cover leaked....iafter that i pulled the cover adjusted the gasket added some shellac, put it back together...ran it a few days later to see if it leaked....and good to go..pumping water, no leaks.....so i put it in the garage.....now! 2 months later i put it on my boat and throw a bucket under it....start it up...no water...shut it off and start it a few more times, nothing!...so now the motors hot and so am i...pull the lower unit and my impeller is toast...a million pieces...and the metal housing is slightly melted into the plastic one.......OK what the hell did i do wrong....i never started it out of water...ever....these pumps aren t free..and i dont wanna mess it up again, can you over torque the housing bolts, because thats my only idea??? as always thanks for thoughts....heres a video of after i did the pump, right b4 i put it in the garage....notice the water coming out of the hole in the front of the mid section...i thought it was strange..and didnt notice it before the new pump....u can also see that im not crazy and it was working http://youtu.be/ekcpd7bGE6Y
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: shreded a brand new impeller....why?

When you say "running in a bucket", I hope that you're talking about a large trash can whereas the water level is a couple inches above the water pump. If not, and the water level was lower than the pump, it ran without water and destroyed itself...... it IS NOT a self priming pump.
 

mark1961

Ensign
Joined
Apr 30, 2007
Messages
940
Re: shreded a brand new impeller....why?

The drum in the video was plenty big enough but the water level was barely over the cav plate, should have had another few inches of water in there so the pump was submerged.....
 

stevo10081984

Seaman Apprentice
Joined
Jan 16, 2011
Messages
40
Re: shreded a brand new impeller....why?

well it was at the same level as it was in my video....a solid 3 inches above the cav plate.....was in a 5 gal bucket...ive done it b4 without consequence...always pumped imediately....but i think your right...new pump nice and tight...super dry....as they say second times a charm....thanks for the quick reply joe
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: shreded a brand new impeller....why?

Yep, you need a lot more water in the barrel.
 

Art Bernard

Banned
Joined
May 4, 2011
Messages
333
Re: shreded a brand new impeller....why?

Why don't you use rabbit ears instead of a bucket?

Art
 

samo_ott

Vice Admiral
Joined
Jun 18, 2006
Messages
5,125
Re: shreded a brand new impeller....why?

While I agree there needed to be a lot more water in the barrel, it did pump water the entire time and it pumped it well. The exhaust had water in it and the pee stream was strong so it does not makes sense.
 

mark1961

Ensign
Joined
Apr 30, 2007
Messages
940
Re: shreded a brand new impeller....why?

Its pretty obvious from the video the pump was run unsubmerged though which as we know its not really meant to.....lots of aerated water in there getting sucked in and revving it wouldn't have helped.....
 
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