'74 15 hp Johnson, Water flow question, w/ video

[schwar74]

Greetings,

I just replaced the impeller in the water pump on my motor. My question is:

Where does the water normally exit the motor? There's water running out of a couple spots up the leg, near the swivels, and then one leaking from a drain hole in the extension piece. Are these normal places for water to exit? Is there enough water coming out of the exhaust relief port, or should there be more? If this is leaking, is there a common place for this to occur? Thanks.
Also, there's a little exhaust visible around the upper swivel. Is this a major problem?
Oh, and if you hear anything else while it idles, I'd appreciate the tips.

Thanks

Scott

 

[dew2]

Re: '74 15 hp Johnson, Water flow question, w/ video

My first guess is that when you reinstalled the lower unit the water tube wasn't placed correctly in the engine. I dont have sound so I dont hear anything.

 

[kfa4303]

Re: '74 15 hp Johnson, Water flow question, w/ video

I agree with dew2. It's pretty common for the water tube to not seat into the waterpump housing properly. IOf you put a bit of vaeline on the end oof the copper tube that goes into the waterpump housing it should help it slide in a little easier. Also, the water should be comming out of the back of the motor on the exhaust leg. You also need more water in your tank. Fill it up as high as you can (top of the bucket) without submerging the exhaust port itself. Keep us posted.

 

[jmendoza]

Re: '74 15 hp Johnson, Water flow question, w/ video

Its pumping fine, but leaking exhaust out the two upper mount holes, and exhaust and water out of the shift rod grommet hole in the bottom of the exhaust housing. BTW, if outboards had LEGs, they could walk on water and you would not need a boat! They do however have exhaust housings, and lower units/gearcases.

 

[jmendoza]

Re: '74 15 hp Johnson, Water flow question, w/ video

deleted

 

[scanman]

Re: '74 15 hp Johnson, Water flow question, w/ video

It's pumpin water just fine. My '74 10hp does the same thing. You can get a kit that'll make it "pee" like newer motors, if ya want, but It'll require pullin the powerhead & drillin a hole in one of the motor's cover plates to install it. I wouldn't recomend it unless you have experience at doin engine & machine work. The exhaust leak is pretty normal for motors this old. It is most likely from one of three gaskets. The one between the powerhead & the lower cowl, or the two that fit into grooves on the upper & lower ends of the exhaust tube. These also require pulling the powerhead to replace them. Unless you're sure you can do this kinda work, I'd prolly recommend you don't mess with it. It'll run ok like this for quite a while. If you're fouling plugs really bad, then it's prolly not burnin all the fuel, & really needs these repairs. I think, as long as it's tuned well, you'll be ok with it. It sounded to me like it's idling just fine, & not tryin to stall out. You may want to put a small tachometer on it, just so you'll see any decline in performance. It will get progressively worse, but there are lots of hours left in it like it is! I can also tell ya that you'll spend more money than that lil motor is worth if you take it to a local repair shop. The amount of labor involved in those repairs will realy run the bill up! If you're not like some of us here, & don't just "enjoy" tinkerin with em, well... don't. That's really a reliable old motor. It's just showin it's age.

 

[schwar74]

Re: '74 15 hp Johnson, Water flow question, w/ video

Thanks for the tips guys. So the water normally exits out of the prop hub? Does it just rund down the with the exhaust? I might pull the foot off the leg (JK JMendoza !!) , pull the lower unit off and recheck the copper water line. I thought it seemed pretty idiot proof to get them in the right place and seated well, but I'll double check it. I need to replace the shift rod linkage anyway. The one that was in there was getting pretty stripped out. Is there any trick to avoid cross threading things on the "far" side? It seems like the two halves of the "clamp" get out of alignment, and then it doesn't thread right. I tried a longer bolt with a nut, but don't really trust it.

Oh, and I did have the water level higher in the tank, but running it through the gears forced alot out. Also, if the water hadn't been this low, I would have never seen this "problem". Does the higher level just prevent lack of water intake when the prop is engaged and cavitating the water?

Thanks.

Scott

 

[scanman]

Re: '74 15 hp Johnson, Water flow question, w/ video

You need to keep the water level up at least 3 or 4 inches above the cavitation plate. Not only does it pull water to cool the engine, wether or not the prop is engaged, but it also creates a bit of backpressure on the exhaust system, which helps it idle a lil more smoothly. As for that linkage, Mine was stripped also. I went to the local Evinrude dealer & paid thier price for 2 new bolts just like the old ones, & thaat problem went away. If you put the motor in drive when you are puttin the foot back on, you should be able to start the bolts by hand. using your fingers instead of a socket or wrench will tell ya if they're crossed up or not. Definately check that water tube placement, it can really be tricky!