20R72R Johnson Won't Stay Running

[Bank2me]

Hey guys we have 1972 Johnson Seahorse 20R72R Pullstart. It has been sitting for 6 years. We tried to take it out last fall and when we tried to start it, nothing happened. So come to find out, no spark. So I changed the points and condensers. And bam we had spark. So today we try it out on the water. About the 3rd pull it sputtered like it wanted to start but didn't. Then finally after about 5 more pulls it fired up and ran. So we go about 200 yards and then it dies. So we pull it once and fires right up. Take off again and it runs fine. Get to the fishing spot and let off the throttle and it died again. So we thought we will fish a bit then move. Fished about 45 minutes then go to start it and nothing happened. Tried about 10 more times and still nothing. So we figured screw it lets swap plugs and try then. So we take plugs out and the look like they had some fuel on them but not a **** ton. Put new plugs in and on the 3rd pull, it sputters. Couple more pulls, it fires up and we drive it back to the launch. Another thing we noticed was the fuel "bulb" felt kind of soft. It didn't feel very firm like it has pressure. Any help is appreciated!!.

 

[racerone]

Once motor is running the bulb will NOT be hard.---Very normal.------Perhaps test run with another tank and hose.-----Replace water pump impeller now.

 

[Bank2me]

Yea we have another tank and bulb we can try next time we are out. How often does the water pump impeller need to be replaced? I know alot about cars but not about outboards lol. Another thing too is that the connection that goes from the fuel tank line to into that plug in on the side of the engine, leaks fuel too.

 

[boobie]

What's the compression on it ? Also will the spark jump a 1/4" open air gap on a spark tester ?

 

[racerone]

Replace the o-ring on the fuel connecter now.

 

[Bank2me]

What's the compression on it ? Also will the spark jump a 1/4" open air gap on a spark tester ?

I have not tested the compression on it. How do you do a compression test on these motors? I've done compression test on cars but never a boat motor. And I cannot confirm on that 1/4 inch spark jump. I do know it has a solid blue spark now when I take the spark plugs out and put it against the motor.

 

[Bank2me]

Replace the o-ring on the fuel connecter now.

What part is that o ring on? The engine end or the fuel tank line end? I should say female(fuel tank line end) or male(engine connector end)

 

[JohnnyGuy]

What part is that o ring on? The engine end or the fuel tank line end? I should say female(fuel tank line end) or male(engine connector end)

The O-Ring is on the fuel line connector coming from the fuel tank (female end; the motor connector is a male end).
If you look at the connector there is a little ball, there's a spring behind the ball which keeps is seated against an O-Ring so that fuel doesn't leak out the hose when you disconnect it.
You can purchase replacement o-rings (Evinrude Part Number is 334913).
Depress the ball in and use a pick to get the existing O-Ring out. Lube the new o-ring up with some fuel, depress the ball and push the new o-ring into place.
Once you look at it, it should make sense to you.

You also might want to try doing a carb clean on it.

Compression test is also simple, a quick search on youtube will give you some easy instructional videos.

 

[Bank2me]

The O-Ring is on the fuel line connector coming from the fuel tank (female end; the motor connector is a male end).
If you look at the connector there is a little ball, there's a spring behind the ball which keeps is seated against an O-Ring so that fuel doesn't leak out the hose when you disconnect it.
You can purchase replacement o-rings (Evinrude Part Number is 334913).
Depress the ball in and use a pick to get the existing O-Ring out. Lube the new o-ring up with some fuel, depress the ball and push the new o-ring into place.
Once you look at it, it should make sense to you.

You also might want to try doing a carb clean on it.

Compression test is also simple, a quick search on youtube will give you some easy instructional videos.

Ok thanks Johnny!! Appreciate the help. I will look into a new o ring. I think he has a new line we can always try too. And yea I'll try a carb cleaning. Do you think the carburetor being gummed could be why its dying?

 

[JohnnyGuy]

If you have another line to try, great!

I am no expert like many others here, but if your carb is all gummed up, its definitely not helping you any .
Its easy and a relatively quick thing to do, then it is done and who knows maybe your problem is solved.

Another invaluable tool is the spark gap tester. It's only a few bucks at your local autoparts store. Ensures your spark is able to jump a properly set (1/4") gap.

 

[JohnnyGuy]

Another thing worth mentioning is to make sure you are using the proper spark plugs and have them gapped correctly. (Looks like Champion J4C gapped to 0.030 is what the evinrude site is calling for).

 

[flyingscott]

To check compression screw in the tester and pull until the needle stops. Absolutely clean your carb and put a good rebuild kit into it. What do the coils look like

 

[Bank2me]

Another thing worth mentioning is to make sure you are using the proper spark plugs and have them gapped correctly. (Looks like Champion J4C gapped to 0.030 is what the evinrude site is calling for).

Thank you for the tips!! I will have to pick up a spark tester soon here and clean out that carburetor. I'll try and do a compression test too on it.

 

[Bank2me]

To check compression screw in the tester and pull until the needle stops. Absolutely clean your carb and put a good rebuild kit into it. What do the coils look like

Oh so like a car engine compression test then. Pretty much crank until the needle stops. Do I need the engine in the water while cranking on it or just on the stand(dry)?

 

[Bank2me]

To check compression screw in the tester and pull until the needle stops. Absolutely clean your carb and put a good rebuild kit into it. What do the coils look like

Sorry forgot to answer the coils tested out ok. If I tested them right. Could they cause the motor to die too if they're bad?

 

[racerone]

When you answer questions you will get results and advice on what to do next.-----" good spark " -----means nothing to me.-----Does spark jump a gap of 5/16" on a test device , yes or no ?----A coil in iffy condition can fail at lower flywheel speeds.-----Motor could go to one cylinder and stall on you.

 

[Bank2me]

When you answer questions you will get results and advice on what to do next.-----" good spark " -----means nothing to me.-----Does spark jump a gap of 5/16" on a test device , yes or no ?----A coil in iffy condition can fail at lower flywheel speeds.-----Motor could go to one cylinder and stall on you.

Yea well I asked you how often you need to replace the water pump impeller because you said "Replace water pump impeller now", and you didn't answer me on that. Same as the "Replace the O ring now" statement you made. Maybe telling me more in detail where the "o ring" actually is instead of just saying replace "o ring" now. Someone else had chimed in and actually told me where the damn thing actually is located. I appreciate the help but god damn. I work long hours and don't have time to mess with this thing until the weekend. I will report back on the spark gap.

 

[racerone]

Sorry I have no idea what level of knowledge you have on your motor.----I just try to point folks to where the problem might be !!

 

[Bank2me]

Sorry I have no idea what level of knowledge you have on your motor.----I just try to point folks to where the problem might be !!

Oh thats ok. Thanks for the help.

 

[JohnnyGuy]

Water pump impeller replacement can depend on a number of factors like how often you run your outboard, what kind of water it's run in (silt heavy water will wear it out quicker). Has the motor been "accidentally" run while out of water/not on muffs?
From my general research (I'll leave it to one of the experts on here to comment further) it should be inspected once a year/every 100hours and replaced every 3 years.