2hp Johnson cooling question

[rjoynt]

I have a 1973 2hp Johnson. I finally got it running. New ignition, carb cleaned. It didn’t pump water so I put in a new impeller. I watched the water tube go into the impeller housing correctly. It still doesn’t pump in my tank. Does it have to be on a boat to get proper water flow? Or, what else am I missing? I put in one of my other two horse motors and it did the same thing. It does pump air out of the pee holes.
Help!

[PugetSoundBoater]

I have a ’77 Johnson 2 hp. Even at top rpm you only get a little spray out the exhaust relief. Put your hand under the discharge and you should get your hand real wet fast.
I was concerned at first when i saw this too.
Is the motor getting hot? Thats the bottom line.

"Some people want to know how a watch works, others just want to know what time it is"
Robbie Robertson

[rjoynt]

Yes, the motor does get hot. I do not have a temperature gauge. I wonder if the wife’s cooking thermometer would work? She has more tools in the kitchen than I have in the shop!!!

[PugetSoundBoater]

Did you have any corrosion at the WP housing /gearcase surface which would cause a leak ? A good driveshaft seal and grommet in the housing is important too.
As i was concerned when i saw the fine water mist exiting the motor,like something isn’t right here, I pulled the Lower unit and put in a bucket of water and hooked up a drill to see how much water came out the WP grommet. It wasn’t much,maybe water exited in a 1/2-3/4 " vertical "stream" ,if you can call it that.

"Some people want to know how a watch works, others just want to know what time it is"
Robbie Robertson

[rjoynt]

I just used my wife’s meat thermometer. I shut off the motor at 200+ degrees at the head.

[fleetwin]

What style water pump do you have? Do you have the original system that uses the gearcase housing itself as an impeller housing, with just and aluminum cap over it? Or, do you have the expensive kit set up with the plastic housing and the SS liner and plate? It is important to realize that these two style water pump set ups use different impellers. So, a mix up will probably result in a no pump situation. I guess at this point I would probably pull the gearcase back off, try to blow through the water tube to check for clogs. Is this a salt water engine? Sounds like you were pretty careful and didn’t misalign the water tube, but anything is possible….

[rjoynt]

The style pump is different than the more ‘modern’ ones. Usually the housing goes over the impeller but this one I had to work the impeller blades down into the housing. I had to mark the driveshaft to make sure I got it on the keyway properly. I ordered the correct impeller, an oddball size. It measured up to the one I took out.
I always blow out the water tube and did it for sure in this one. It is not a saltwater motor. We thankfully do not see many here in Ohio.

[billw]

A marginal pump will not pump well in the tank, for sure. The trouble with twos is that, unless you buy the expensive, redesigned pump kit, you have to deal with the same old, worn impeller "housing," because it is part of the lower unit itself. It may or may not, pump better on a boat. The new kits pump like crazy but are pricey. Between the lower crank bearing problems, worn cylinders and the pump dilemma, these motors are, at best, a labor of love. They are surprisingly difficult to "flip" and clear any profit whatsoever.

Long live American manufacturing!

[rjoynt]

Does anyone have the part number of the new replacement pump? I have never heard of it before.
Thanks.

[fleetwin]

387362 supercedes to 763736 @ $52.59, this kit contains all the bits and pieces to update the pump….

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