won't pump water

shane ames

Seaman Apprentice
Joined
Aug 25, 2010
Messages
47
I am stumped and have a problem to post to the iboat gurus. I have a 1968 mercury 500 thunderbolt 50 hp outboard. I replaced the impeller yesterday and it still won't pump water. I know i did it right, fins turned propper direction, key in place, the cup and rest of the water pump cover is in good shape and I snugged it back together good.....I started it and no flow from the pee hole I only let it run about 20 seconds on muffs for fear of overheating. was that long enough? I cleared some crap out of the rubber hose to the pee hole and actually took it off and put it back onto make sure it was clear.

1. is it possible that the copper hose connected to the top section of the water pump cover is clogged. And if i take it apart to check this will i have to replace the seals in the water pump since i just put them in yesterday?

2. If not the copper water tube what else could be plugged up and how do i get to it to clear it out?

3. I connected the muffs over the four small holes just above the propeller on the lower leg of the motor, is this the proper place to put them or does anybody have a picture of the right place to put the muffs?

P.S the old impeller came out whole no chunks of rubber missing to clog up the system.

Any help would be appreciated,
Shane
 

Wingedwheel

Lieutenant Junior Grade
Joined
Jun 16, 2009
Messages
1,071
Re: won't pump water

You need to run a wire or use compressed air to give the pick-up tube a good cleaning. Also check and make sure the water is getting to the pump. You shouldn't have to take the impeller back out so your seals will be fine.
 

rosser1

Petty Officer 1st Class
Joined
Apr 5, 2009
Messages
360
Re: won't pump water

take a long wire, slightly flexable, while motor is running and slide it up in to pee hole, i dont think 20 sec will hurt anything, my 80's 90 mariner takes a few secs of running to get water. make sure water is on wide open. keep pushing wire in and pulling out while motor is running, til water gets to flowing better.
 

ohioriverat

Petty Officer 2nd Class
Joined
Aug 7, 2011
Messages
115
Re: won't pump water

I use weedeater string, works great along with air. are you sure you lined up the copper tube with the pump housing?
 

shane ames

Seaman Apprentice
Joined
Aug 25, 2010
Messages
47
Re: won't pump water

thanks guy keepit coming I will try again this week . the copper tube was supposed to come out with the lower unti right. is it possible that the unit will go back on with the copper tube not in placecorrectly in place. it is my first boat t really s so i'm not really sure what i'm looking at
 

Gomer50

Chief Petty Officer
Joined
Sep 5, 2009
Messages
507
Re: won't pump water

Normal the copper tube stays attached to the mid section and doesnt come off when the lower unit is detached to change the water pump.When reinstalling the lower unit that copper tube has to be in the correct hole up in the mid section,in order to do this right the power head has to come off the mid section taken apart and the tube reinstalled correctly.But I put duct tape around the top of the tube and with a flashlight shoved the tube up where it is supposed to be.Put the lower unit back on and was good to go.Doesnt solve the problem in the long run but it works.
 

shane ames

Seaman Apprentice
Joined
Aug 25, 2010
Messages
47
Re: won't pump water

so if I take the tube out of the lower unit and put it back in the leg will it shove up in to place easily or do I need the duct tape to make the end of the tube fatter to sort of wedge it up in. then put the lower back on.
 
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