69 Johnson, how much water out peehole?

[knucklecars]

My 1969 Johnson 40hp runs great now but I noticed the water out the peehole is not a stream, just spitting out with steam there is water coming out but not anywhere as much as my buddy with a much newer motor...how much should be flowing at idle and at full throttle?...time to change impellor or pump?...is this a lot of work?...thanks in advance.

 

[R.Johnson]

Re: 69 Johnson, how much water out peehole?

The hole you are taling about is an exhaust by-pass. This will spit water when the thermostat opens. At full throttle, there is a pressure relief valve that open's, which will flow more water. The thermostat, and pressure relief valve are located at the top of the cylinder head. Under the thermostat cover is the thermostat, plastic thermostat housing, pressure relief valve, pressure relief spring in that order. You should be able to hold your hand on the cylinder head for a short time without burning.

 

[knucklecars]

Re: 69 Johnson, how much water out peehole?

Thanks R.Johnson....so the steam that is coming out this same hole is normal as well as the spitting water at idle?<br />Do these older motors flow as much water as the new ones?..a friends 2004 was flowing like crazy at idle...I couldnt really see how much was coming from mine at full throttle..should there be a good flow?

 

[Paul Moir]

Re: 69 Johnson, how much water out peehole?

The idle exhaust goes out that hole as well so it's pretty steamy.<br />What you're seeing is all the water exiting the engine. These don't work very much like a modern outboard with a tell-tale as the cooling system is hardly pressurized.<br />There should be a good amount at full throttle.

 

[CATransplant]

Re: 69 Johnson, how much water out peehole?

Paul,<br /><br />Good to see you here again. Doesn't a lot of the water circulated through the engine go out underwater with the exhaust on these? I mean what comes out that relief hole isn't ALL the water being circulated, is it?

 

[knucklecars]

Re: 69 Johnson, how much water out peehole?

Thanks guys...the motor seemed to be cool enough after being out at full throttle for a while, so I assumed maybe as CAt mentioned that water may circulate under the water line and is not to visible to see circulation?...Other then that all is perfect!...I am thinking of buying a much newer boat, but I just may have to keep this one to tow the new one in when it breaks down...hahaha

 

[CATransplant]

Re: 69 Johnson, how much water out peehole?

You should be OK, but if the impeller hasn't been changed on your old Johnson, you might want to do that soon. It's better to be safe than sorry.<br /><br />Most folks here recommend changing the impeller on all engines you don't know the service history of, and every two or three years thereafter.<br /><br />It's good advice, and can save you costly repairs later.<br /><br />It's not a terribly difficult job, but is best done with manual in hand.

 

[Paul Moir]

Re: 69 Johnson, how much water out peehole?

CATransplant - I'm not 100% sure on the super quiets, but it's true for the plain mid-section Big Twins. No water goes in with the exhaust like on almost all other outboards.<br />Thanks for the kind regards. I was away for a while sailing and fixing up the family cottage, etc. It's too nice here most of the time for sitting at the computer.

 

[CATransplant]

Re: 69 Johnson, how much water out peehole?

Good job, Paul. It's important to get away. We've been trying to hold down the Big Twin fort while you were away. Decent results, but you were definitely missed.<br /><br />I'm going to have to study the water flow on the SuperQuiet model. The bellows that connects the exhaust tube to the relief hole doesn't have any sort of separate water connection. It's just a bellows. To me, that says that water and exhaust are both coming out the relief, but not exclusively. It appears that the two are simply dumped into the exhaust area, which means that some of the water must be going out with the exhaust underwater.<br /><br />That's reinforced by the fact that there's little increase in waterflow out the relief hole based on engine RPM, once you get above idle.<br /><br />I'll have another look at the diagrams.