HELP!! 35hp johnson 1979 major water problem HELP PLEASE!!!

[FISHBONE74]

I have posted several times and had lots of great help and ideals but i still have the same problem my 1979 johnson 35hp will not pump water when the engine starts. I have it sitting in a very large trash can full of water and as long as the starter is engaged turning the motor over i have a steady flow of water beeing pumped out of the tale tale but as soon as the motor fires and is running on its own the water immediatly stops. I have changed the impeller 2 times i have replaced the key 2 times replaced the thermostat all of the gaskets around the water jacket replaced the gaskets around the exaust side i have flushed water through the motor forwards and backwards i have taken the lower unit off so many times i can remove it with my eyes closed. I bought this boat in november of 07 and have not made it to the water yet and summer is almost over. Any body with any sugusstions would be greatly appriciated.

Thanks in advance
Fishbone74

 

[tashasdaddy]

Re: HELP!! 35hp johnson 1979 major water problem HELP PLEASE!!!

in a barrel, the exhaust can blow the water away from the water pickup. try in in the water and see what happens. just back down the ramp and try it.

 

[ezeke]

Re: HELP!! 35hp johnson 1979 major water problem HELP PLEASE!!!

The pumps are not self priming, so the water in a barrel needs to be higher than the water pump whenever the motor is running.

Also, be sure that the air bleed vent at the top of the water pump housing is open or the water pump will not be able to stay primed.

 

[FISHBONE74]

Re: HELP!! 35hp johnson 1979 major water problem HELP PLEASE!!!

where might i find the air bleed vent or what does it look like also thanks to everyone for there help. any more ideas are welcome i need all the help i can get. also can you look at the fly wheel and tell if the key is broke or do you have to remove it to check
thanks again
fishbone74

 

[ezeke]

Re: HELP!! 35hp johnson 1979 major water problem HELP PLEASE!!!

If you look at the metal cup that holds the impeller, you will see that it has a small round hole at the top. The hole leads to a slot that runs outward in the water pump housing. This vents the air from the housing so that the water can displace it.

It is fairly common to find the slot blocked when the water pump is not fuctioning properly.

 

[FISHBONE74]

Re: HELP!! 35hp johnson 1979 major water problem HELP PLEASE!!!

ok i will take it apart and check it and let you know
thanks again
fishbone74

 

[Rogue03]

Re: HELP!! 35hp johnson 1979 major water problem HELP PLEASE!!!

Check the head gasket, I have had compression push the water back so there is no flow when the engine starts.