1960 johnson 40hp

[lodown]

I was wondering if anybody would know what could be wrong. I installed a new water pump complete kit because i couldn't get water to spit out the hole in the back when it's rpms are up. it will pump out untill about half throt and then it quits. I run it wot for a little bit and back off and the water is hot spitting out. i let it idle for a little bit and cools off. What could be wrong i had this same problem with the old water pump to. any help would be great.

 

[F_R]

Re: 1960 johnson 40hp

Do you have the thermostat in? There is a white check valve below the thermostat housing, is that in there? Sounds like you are sucking exhaust into the pump intake. Deep sixing all the "unnecessary" thermostat parts is a good way to cause that.

 

[Windykid]

Re: 1960 johnson 40hp

Was the impellar key reinstalled?

 

[lodown]

Re: 1960 johnson 40hp

Yes the key is in the water pump impeller, I have never been in the thermostat part. should i take the check ball out or just clean it up?

 

[CATransplant]

Re: 1960 johnson 40hp

Just a note you might want to consider:

I had a 1958 RSD-20, the 35 hp equivalent of your Johnson. The outlet you're talking about is just an exhaust bypass, not a telltale. At low rpms, it lets a little exhaust (along with water) out to keep from building exhaust pressure at idle.

At higher RPMs, with the prop turning, almost all the exhaust goes out the exhaust port in front of the prop. I remember seeing virtually nothing out that exhaust port when underway on mine.

Like you, I worried about this, so I took the cover off my engine, ran at WOT on the lake for about ten minutes, then idled down and felt the water jackets. No problem...the engine was running normally.

It's a mistake to consider that exhaust relief port as a cooling system telltale. It's not there for that purpose. Try my test on the water. I'm betting you're just fine.

 

[lodown]

Re: 1960 johnson 40hp

yeah i did try that and when it was wide open for a while i dropped down to an idle and the water spitting out was real hot and steamy. How hot should it be after full throtle? I had open for maybe 5 min and the water spitting out hot and steamy. i could only keep my hand under for a few seconds. it was that hot.

 

[jimmbo]

Re: 1960 johnson 40hp

the stats are about 140 degrees, which is hot enough not to be comfortable.

 

[CATransplant]

Re: 1960 johnson 40hp

yeah i did try that and when it was wide open for a while i dropped down to an idle and the water spitting out was real hot and steamy. How hot should it be after full throtle? I had open for maybe 5 min and the water spitting out hot and steamy. i could only keep my hand under for a few seconds. it was that hot.

A few seconds is fine. That water should be around 150 degrees. That's hot, but not overheated. Besides, you're getting the water mixed with exhaust gasses. Your engine sounds fine.

Instead of trying to feel the water, feel the side of the engine, near the heads. If you can hold your finger on the metal for a few seconds, you're running just about right.

That mid leg outlet has a bellows that connects directly to the exhaust passage in the leg. It's not like the telltale that modern outboards have. That's why the volume of water doesn't increase when you speed up the engine. In fact, it decreases, since the prop creates almost a suction that draws the exhaust and water out of the engine at the bottom.

Feel the block of the engine, not the water. If you're getting water at idle and lower engine speeds, then the impeller is working fine.

Go enjoy your boat.

 

[samo_ott]

Re: 1960 johnson 40hp

And if you have access to one, an infrared thermometer works great or can be bought for about $50. They can tell the temp by just pointing at whatever and clicking on the button and you get a reading in under a scond!

 

[lodown]

Re: 1960 johnson 40hp

Thanks guys. I just took the thermastat cover off and the thermastat is shot. I also see the check ball, it looks good. can i run without it. I pulled another motor apart i have and there isn't one in there to steal, It's already missing. Should i replace it before i take my boat out or will it not matter.

 

[tashasdaddy]

Re: 1960 johnson 40hp

it will run cold, causing poor combustion, carbon buildup.

 

[samo_ott]

Re: 1960 johnson 40hp

Cold is better than hot but I'd get a thermostat!

 

[lodown]

Re: 1960 johnson 40hp

is it ok to run for a couple days with out the thermostat till i get one in from the marine shop. or should i wait till i get one before i take my boat out again?

 

[tashasdaddy]

Re: 1960 johnson 40hp

a couple of days won't hurt. but get one, people have a tendency not to do it after the fact. then they don't understand why, they are having problems.

 

[lodown]

Re: 1960 johnson 40hp

ok thanks for the help everyone. i will get one on order today so i can do some fishing and have some fun now that i know the water pump is working right. THANKS