Johnson 5.5 CD-13 carb issue.

[joshadurham]

I went to barrel tune my 56 johnson 5.5 today, and found it to not tune properly, and run erratically. I pulled the cover off and sprayed starter fluid around the carb while it idled, and sure enough it choked out. Also while its running I can cover up both sides of the intake, and it doesnt pull hardly any suction, and remains running. Is there a common spot that these old outboards pull a vacuum? It has run beautifully up until a trip to the lake a couple weeks ago, when it decided to quit, then run again for a short while at low speed, then quit again. It progressively got worse until we eventually had to get towed back to the dock. impeller was pumping water the whole time. Got it home, and tore down the carb to inspect, and did a compression check, and all was good. Now its running, but not good. Any thoughts? Thanks.

[Mumbles]

There are drain holes in the bottom of the silencer so you won’t be able to kill the motor by plugging up the ends. If the carb and compression are ok, how’s the spark? If the motor has it’s original coils in it, I can guarantee they will be cracked and will need replacing. Cracked coils can let the motor run for a while but as they warm up they will start to fail. If you remove the inspection cover on top of the flywheel, you will be able to see what your coils look like. If they look anything like the ones in the picture, it’s time for repairs.

[chuckw]

Never use starter fluid to start and outboard, they drain all the oil lube from the internals.

[joshadurham]

I just checked the ignition coils, and they look clean, and like new. They are green plastic, and look nothing like what you have pictured. Thanks for the suggestion.

[joshadurham]

quote chuckw:

Never use starter fluid to start and outboard, they drain all the oil lube from the internals.

I wasn’t using it to start the engine, I was spraying it around the carburetor while the engine was running to check for a carb vacuum leak. Thanks.

[RICHARD A. WHITE]

quote joshadurham:

quote chuckw:

Never use starter fluid to start and outboard, they drain all the oil lube from the internals.

I wasn’t using it to start the engine, I was spraying it around the carburetor while the engine was running to check for a carb vacuum leak. Thanks.

Spraying around the motor while running is how they sometimes check for vacuum leaks on a 4 cycle motor. What happens is when there is a leak it sucks the fluid into the motor and it will rev higher….that means you may not be spraying it directly into the motor, but if it gets in there, it can still cause damage. Make sense?

We just know from experience that one should never use that stuff on a 2 stroke..

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[joshadurham]

Ok yea that makes sense. Maybe it doesnt have a vac leak. Maybe its just getting enough ether through the intake to make the rpm drop. I could be looking at an ignition issue. How can I test the coils, other than the "see if theyre cracked" method? I have a multimeter. Thanks

[RICHARD A. WHITE]

Try this video…:

https://youtu.be/TbBCaZjXY-Y

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[joshadurham]

Thats great thanks!

[fleetwin]

Well, the problem you describe could be caused by just about anything. Always start with the simplest basic stuff though.
I’m assuming you have checked compression, you advise the water pump seems to be working OK as well. Lets start with your fuel/oil supply, is it fresh this year? Have you checked the filter bowl for signs of water? The filter may be plugged also, even if it looks clean, you might try running it without the filter. Perhaps the pressure tank isn’t developing pressure or there is a leak in the pressure line. Try running the engine while pump the primer button, see if that helps.
The ignition system may look OK, doesn’t mean it is. You might try checking for spark when the engine quits and won’t restart, it should be able to jump a 1/4" gap.
I guess I have skipped over the simplest of solutions though, you may want to try a new set of plugs, even if your plugs are new, doesn’t mean they are any good.

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