1960 Johnson 40hp Water Pump Problems

[AMD_237]

Re: 1960 Johnson 40hp Water Pump Problems

I disconnected the pressure release valve and took off the lower unit again to look. Black oil came down the exhaust tube that travels to the lower unit from the powerhead. Maybe a new head gasket would fix a lot of the problems that I am having with the motor, including the water cooling system. Would an improperly seated valve in the head cause the same problem as a worn head gasket, letting combustion into the water lines?

 

[freddyray21]

Re: 1960 Johnson 40hp Water Pump Problems

there are no valves in the head. While you have the lower off hook a drill to the drive shaft and spin it clockwise while you have it in a barrell and see if it pumps.

 

[kandil]

Re: 1960 Johnson 40hp Water Pump Problems

Compression test are done throw the spark plugs hole you may have a clogged water way in the head I have seen clogged passages with salt corrosion and mud try to hock your garden hose to the tub that goes up above the water pumb I use an oil quart cab that looks like a funnel it fits on the garden hose perfectly and see if you can clear the passages?this are some photos of a Yamaha water passages clogged
PS WEAR GOGGLES

 

[freddyray21]

Re: 1960 Johnson 40hp Water Pump Problems

Black oil came down the exhaust tube that travels to the lower unit from the powerhead.

this is normal. It is the unburnt oil and gas mixing with the exhaust.

 

[AMD_237]

Re: 1960 Johnson 40hp Water Pump Problems

I took the head and gasket off and noticed there was oil on the gasket like it had been leaking. I think the theory about replacing the gasket is one of the problems for sure. I look at the inside of the cylinder head where the spark plugs enter the cylinder and it had a small amount of oil but also there was something yellow. Not sure what that could be but I am pretty sure I need to next go to a new head gasket because I checked the water passageways through the head and they seemed clean and like something has been passage through slightly.

 

[Grem]

Re: 1960 Johnson 40hp Water Pump Problems

Maybe stating the obvious, but when you replaced the impeller, did you make sure to locate the key correctly in the groove to lock the impeller in place on the shaft?

 

[AMD_237]

Re: 1960 Johnson 40hp Water Pump Problems

Yeah, the impeller is turning correctly I double and triple checked that before I put the lower unit back on. I think the water circulation is getting better just not where it should be quite yet.

 

[Nietos]

Im having the exact problems on my johnson 40hp super seahorse

 

[racerone]

Best to start a new post.-----And put lots of water in your test bucket.