56 Johnson 7.5 water pump problems

[6x6TRex]

Hey everyone! I have a 56 Johnson AD-10M 7.5HP outboard serial #1389112 that I got from my grandparents. It had sat in their barn for 20+ years. I replaced the water pump and got it running, had to replace both coils, spark plugs and clean out the carb and gas tank.

My problem is the water pump isn't pumping any water. I pulled the powerhead off and spun the driveshaft with a drill but didnt get any water. I spun it backwards and did get bubbles out the water intake. Do I need to RTV the pump housing or something? Also I checked to see if the passage was blocked but it looks like it goes down 6"-7" then ends!?!
I'm normally pretty good figuring stuff out (replaced the powerhead on my 86 Merc 150 by myself with no manual) but this little motor has me stumped!

 

[Chinewalker]

Re: 56 Johnson 7.5 water pump problems

Are you sure the water tube grommets between the waterpump housing and exhaust housing are in good shape - not folded over or rotted, etc.? How deep do you have the unit submerged? To prime, water level must be over the waterpump housing.

 

[6x6TRex]

Re: 56 Johnson 7.5 water pump problems

How deep do you have the unit submerged? To prime, water level must be over the waterpump housing.

About 4"-5" above the water pump

Are you sure the water tube grommets between the waterpump housing and exhaust housing are in good shape - not folded over or rotted, etc.?

Grommet, what grommet? Turned motor upside down and sure enough the grommet is jammed up into the exhaust housing. Had to beat it out with a welding rod and hammer but its still in good shape!
Put some RTV on the housing and grommets then put everything back together and she runs great!

 

[57johnsonmich]

Re: 56 Johnson 7.5 water pump problems

Are you sure the water tube grommets between the waterpump housing and exhaust housing are in good shape - not folded over or rotted, etc.? How deep do you have the unit submerged? To prime, water level must be over the waterpump housing.

Submerging the lower unit below the level of the water pump worked for me....thanks for the great advice...I had just replaced the waterpump on a 1957 7.5 Johnson and was not getting water out the back port...dipping it deeper worked like a charm..