4hp Johnson Water Problems

[Holy Shamolee]

I have an older Johnson 4hp. It does not pump any water. I replaced the impeller and still no water.
I took the leg off. The hole where the water comes out was plugged tight. I cleaned this out.
I tried to blow air through the motor when the leg was off. I cannot get air to flow through the motor. I don't know if there is a valve or thermostat or something blocking this or if air should flow.
I can push a coathanger wire in the inlet to the top of the motor with no problem and also the outlet hole. They do not seem to be plugged at all. I don't seem to be able to find access to any other water holes.
I put it back together and started it up and water still does not flow.
Any ideas?
Thanks

 

[Rick.]

Re: 4hp Johnson Water Problems

Not sure about the year here but my experience is based on 71 and 73 models. There is no thermostat so that isn't the problem. You say the water tube was plugged solid. With what? I will assume it was mud. I would recommend you drop the leg again and connect a hose directly to the water tube. Turn it on low (the hose not the motor) and hopefully after the blockage has some soak time it will push free of the motor.If you like you could pull the head and see if your getting any flow at the head but I would try the hose first before pulling the head. One other thing is to make sure your water level in the barrel is well above the pump housing, the higher up the leg the better. Best of luck. Rick.

 

[Vic.S]

Re: 4hp Johnson Water Problems

Tell us the year, or the model number, then we know what we are dealing with or can look up some info perhaps.

I do not understand what you mean by "the hole where the water comes out was plugged tight" Generally the bulk of the cooling water comes out under water with the exhaust. There is I guess an exhaust relief outlet port on the back of the leg from which some exhaust and some water will be blown.

On an older 4hp I do not think there will be a tell tale (aka peehole) but knowledge of the model/year should help to confirm that. likewise, as Rick says I do not think there will be a thermostat.

It should be possible to blow air or water through the engine via the watertube. If you cannot and the tube itself is not blocked then the water passages in the engine are most likely blocked.

 

[Holy Shamolee]

Re: 4hp Johnson Water Problems

It's actually a 4.5 hp
Seahorse.
Model # J5RHCTA.
It was plugged with a white powdery substance.Like the white stuff on a shower door.
I can't tell if water is coming out the exhaust as it is in a barrel. the weep hole was plugged. It is still not working.
If I take off the head, will I have access to some of the cooling channels to see if they are plugged.
I turned the motor upside down and filled all the holes with WD-40. I left it like that all night.
I hooked up my compressor 130lbs and cannot blow through the motor.
I got no idea how old it is. I bought it 15 yrs ago and it looked pretty damn old then.
Thanks

 

[Vic.S]

Re: 4hp Johnson Water Problems

That model number makes it a 1983 model (CT = 83)

It does not have a thermostat as far as I can see nor a telltale.

The outlet you had to unblock is on the back of the leg near the top with a rectangular cover over it ? If so that is the relief outlet. When running you get mostly exhaust gas out with a few drops of water (or you should do).

The waterways in the head are very likely blocked. They follow that figure of 8 you can see around the head.

I reckon you'll have to take the head off and the exhaust cover plate on the side of the cylinder block

 

[Rick.]

Re: 4hp Johnson Water Problems

I'm an inlander with no salt water experience but do you think that crud could be salt? Anyway, yes you sill have some access to water ports if you remove the head. If the holes in the leg are blocked you might try opening them with a small drill bit. Rick.

 

[Holy Shamolee]

Re: 4hp Johnson Water Problems

OK . Took the head off. There was good access to the waterports for sure. Figure 8 thing as someone mentioned. They were jam packed with salt. Cleaned it all out good, poked all the holes out with stovepipe wire. Blew it out with compressed air. Put it back together and there is lots of water flowing now. Lots of water out the weephole above the little exhaust port near the top of the leg. I'm sure lots out the exhaust too as the air was flowing good there too.
Thanks for your help.

 

[Rick.]

Re: 4hp Johnson Water Problems

That's great to hear. I've heard on this forum of some type of chemical you can do a flush with to remove salt deposits. Not sure if your interested but if you are I would start a new thread about removing salt from an older engine. Hope you enjoy your motor. They run forever on a gallon of fuel. Rick.