mercrusier 80 water not pumping through to engine.

spearman

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Aug 15, 2008
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Recently replaced impeller, water pump housing in lower, water tube and the seals for water tube in lower and upper. When using muffs at full blast no water comming through hose inside boat. I can run water backwards and it comes out pee hole and bottom of prop with no problem. I also used created suction on water hose inside boat and can pull water through but will not pump through by itself. Today I put boat in the water lowered stern drive all the way, ran engine still no water comming through, but once again created suction from inside boat and got some water to come through, but no consistent flow. Reconnected water hose to block and ran in forward gear for about 5 min. hoping that water would flow to engine. Temp light came on I shut down and put back on trailer. Intend to pull entire stern drive in one peice to see if there is problem where it hooks into bell housing around water shuter as i can see water dripping on top of shift shaft. Please help with any other ideas as to what problem may be.
Additonal history on repair: had boat with mechanic, he was not excited to see it. They replaced hydraulic shift actuater and rebuilt carb and got boat running and shifting great. Prior to this the water pump would pull through fine. Was told that boat was not cooling properly and they would fix. Next thing I know they tell me the shift shaft, reverse lock, water tube and the water pump housing were damaged when they took it apart. My guess is they went into the lower to replace impeller but it is at the top. I managed to find all these parts in lower and have replaced. Boat runs and shifts great but just not cooling. Help!

Spearman
 

Bondo

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Re: mercrusier 80 water not pumping through to engine.

Ayuh,...

Are you saying you Replaced the Impeller, the Housing,+ the water Tube,..??..??

After you pull the drive, Split it apart,+ Look at where the Water Tube goes into the upper unit,...
My Guess is,...
That little housing is Trashed,+ replacing it is about Impossible.....
 

spearman

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Re: mercrusier 80 water not pumping through to engine.

Thanks for the response Bond-O!
Yes, the impeller at the top was replaced as well as the water pump housing, or adapter assembly in the lower, just above pick up holes and the water tube. When I replaced the water tube and seals on either side I inspected the small upper housing and from the outside and where seal goes it looked fine and I put a new seal in there. I have a new upper housing, but after having to bang the old lower housing out with a punch I did not try to get the upper out. It has four phillps head screws and its way up in there, hard to get at. Not to mention it has probaby been there since 1967. Perhaps if I had the upper off the boat it would eaiser to get to. Is there no other item that could stop the water flow after the upper housing?

Spearman
 

Bondo

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Re: mercrusier 80 water not pumping through to engine.

Recently replaced impeller, water pump housing in lower, water tube and the seals for water tube in lower and upper.but will not pump through by itself.

Ayuh,... You didn't forget the impeller Key did you,..??

It sounds like you've done the Testing with the hose,....

I gotta believe that for some reason,... The Pump just isn't Pumping,....
 

spearman

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Aug 15, 2008
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Re: mercrusier 80 water not pumping through to engine.

Problem is I did not replace the impeller, a mechanic did. I replaced all the other items listed. How can I tell if this impeller key is installed or installed properly.

Spearman
 

Bondo

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Re: mercrusier 80 water not pumping through to engine.

Ayuh,....

Take it apart,+ Look....
 

spearman

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Aug 15, 2008
Messages
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Re: mercrusier 80 water not pumping through to engine.

Will do! Hopefully this will take care of problem. I'll try this before pull stern drive.

Thanks for your help, I'm out.....

Spearman
 
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