water flow problems

[kennethc81]

so ive rebuilt my water pump and replaced all thermostats and preassure springs pretty much the whole thermostat assembly. im getting low to no water flow from the tell tale and i pulled the hose that connects the thermostat housing to the cylinder head and started it no water came out. now i have pulled the lower three times to check my water pump job i do what the book says, i face the impeller blades in a clockwise position i make sure the key is in proper position i bolt everything up and manually turn the drive shaft to make sure the impeller is turning it dose. but still no water flow. before i pull the lower unit for the forth time any idea what could be happening. also is there a gasket that fits in between the lower unit and the middle unit i cant find any but i can see were one once was
thanks
oh its a 115 johnson crossflow model j115tleor 95 year

 

[waynehol]

Re: water flow problems

There's no gasket between the lower unit and the mid unit normally.

When you install the lower unit, there should be a water pick up hose/tube that seats right on top of the outflow of the water pump. Is that connecting when you raise the lower unit? is it blocked by something?

 

[kennethc81]

Re: water flow problems

at first i found today that the tube was not sealing with the housing due to the diameter being to wide, i replaced it and tested the fit first and it was nice and tight i installed and still same problem.

 

[waynehol]

Re: water flow problems

How are you testing? Are you using a muff or a test tank or in the water? Best bet to float the boat and make sure the water pump is completely submurged in water when you test.

 

[kennethc81]

Re: water flow problems

i am using muffs to test, before i rebuilt the water preassure was good with muffs so i dont know if a new impeller, housing and seals would make a difference

 

[waynehol]

Re: water flow problems

Im stumped. I did however see this other thread. Maybe it will help?

http://forums.iboats.com/showthread.php?t=327864&highlight=water+pump

 

[Britar]

Re: water flow problems

There is a gasket that seals the exhaust port between the midsection and the lower unit. But that shouldn't affect the water intake or performance of the cooling.
Have you tried jamming a hose in the midsection water tube while the lower unit was off and the thermostat housing removed? You should see water pour out of the thermostat.

#30

 

[kennethc81]

Re: water flow problems

no i havent tried that but due to were the thermostat housing is located im nervous about taking it completley off. the lower couling blocks just about all accsess to it and with the pressure springs it will be a major pain to put it back together i havent figured out a way to at least lower or remove the couling but i will lossen the thermo housing and see if i get water that way.