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1973 Johnson 40 hp.. more water problems..grrrr

G

Gorto72

Member
:mad:Ok...I have had a few problems with my 40hp Johnson 1973..Found the water tube was broken and i have since replaced it, along with stripping the power head down and cleaning all the heads, pistons, water gunnels and even retapped and threaded all the bolt holes and replaced all the gaskets..
I re asembled and startted the motor in lest then 2 turns, It runs beautifully..Just no water comeing through...
So, I once again removed the gear box. Connected a hose directly to the water tube and I have compleate water flow like it should (unlike previously)..I disassembled the NEW water pum and rechecked it all...It all seems good and the impeller is even spinning by hand on the drive shaft...
Is there anything I may have missed as to why its not pumping up to the power head...???? Thanks guys..
 
Don't know about your year or model, but on all the ones I have ever worked on the impeller is not supposed to spin on the driveshaft. There should be a pin or a key to keep it from spinning on the driveshaft. That said, there are two parts to any pump. Intake and discharge. If everything else is OK, I would remove the pump, make sure the intake isn't plugged (rotted screens? Mud daubers?) Beyond that, the only thing I can think of is that the watertube may not have been connected to the pump correctly when the LU was installed.
 
Make sure:

1 - The pin is installed in driveshaft so that the impeller is forced to turn withinn the impeller housing when the driveshaft is turned.

2 - The impeller housing water tube grommet is greased slightly to allow the water tube to slide in easily.

3 - The water tube glides into the impeller housing grommet properly and DOES NOT hit the top edge of the grommet which would fold the grommet over effectively creating a shut off valve.

4 - If running the engine in a barrel, be sure to have the water level 2 or 3 inches above where the water pump is located, otherwise the pump can draw air.
 
Thanks Jo,but I got it sorted...
Everything you suggested mate is a standard check to me ( mechanical minded...lol ) but there was another option...
I used a factory water pump replacement kit and everytime I checked and re checked the impeller the new pump houseing was hard and tite to remove or fit..
so at 2am this morning I woke up and thought maybe its too tite and not screwing down tite enough and creating a propper seal..( why dont I have good dreams)
Today I removed the pump houseing, used a flappy disk on my grinder and cleaned up all along the mould mark. The pump now easily fitted into place, screwed it back in, re conected and hey presto...It was working like a fire house..lots of water and presure...
So the actual problem was the pump wasnt sealed properly and failed to fit down tite...thanks again...
 
In all my years experience, that's a first. The factory's getting sloppy..... quality control better crack down.
 
yer I know mate, best I could do for now though, but if thats the worst complaint then Im happy..lol
Im going to try a bigger tank this week if it stops raining...
 
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