28 spl johnson outboard backfire problem

[yokos]

I can't figure out why my outboard keeps backfiring! I changed the spark plugs, plug wires, starter coil, spark plug coils, and even bought a brand new carburetor! STILL BACKFIRING! HELP PLEASE!

 

[Bob_VT]

Re: 28 spl johnson outboard backfire problem

Backfiring or "sneezing" is usually caused by a lean condition. You need to check a few things.......

Check your ignition system and your carb. Sometimes a tiny airleak at the base of the carb will cause that.

Welcome to iboats.

Are you following a manual or winging it? I would strongly suggest the proper manual

 

[Chinewalker]

Re: 28 spl johnson outboard backfire problem

Has it ever run for you, .ie is the motor new to you? My first thought was that the coil wires were reversed.

 

[Grub54891]

Re: 28 spl johnson outboard backfire problem

Or a leaky crank seal will draw air.

 

[Faztbullet]

Re: 28 spl johnson outboard backfire problem

Does it backfire out exhaust or carb?? Exhaust is usually a ignition/timing problem...have you checked flywheel key?

 

[yokos]

Re: 28 spl johnson outboard backfire problem

Thanks for the responses! It's backfiring from the exhaust.

 

[boobie]

Re: 28 spl johnson outboard backfire problem

As said above, check the flywheel key.

 

[cajuncook1]

Re: 28 spl johnson outboard backfire problem

I posted this to help another member, it may help you with the ignition.


Well, after having camera issues and having to use an older video recorder, I finally finished the video. The video was an 1hr and 7 min long, but I had to break up the video into 10 min segment to place on you tube. I had not originally wanted to put on you tube, but photobucket was acting up.




Hopefully will give you a visual and help you some.

Evinrude Gale and Johnson ignition video 1

Evinrude Gale and Johnson ignition video 1 - YouTube


Evinrude Gale and Johnson ignition video 2

Evinrude Gale and Johnson ignition video 2 - YouTube


Evinrude Gale and Johnson ignition video 3

Evinrude Gale and Johnson ignition video 3 - YouTube


Evinrude Gale and Johnson ignition video 4

Evinrude Gale and Johnson ignition video 4 - YouTube


Evinrude Gale and Johnson ignition video 5

Evinrude Gale and Johnson ignition video 5 - YouTube


Evinrude Gale and Johnson ignition video 6

Evinrude Gale and Johnson ignition video 6 - YouTube


Evinrude Gale and Johnson ignition video 7

Evinrude Gale and Johnson ignition video 7 - YouTube



Sorry the camera and video edit software was not all that great. It is very hard to see the spark when I am checking with the spark checker, but in the end I get both set of spark plugs to fire even though you may not be see them. Anyway, I think you will get a good idea how to work on OMC ignition from 1950 to 1973. I know I repeat a lot and videos are a little long, so I had to break each segment into 10 min. I am not that good a videoing or editing.

Hope it helps anyway. Oh, sorry about the caption that the video edit was not activated so it is a little distracting.

Cheers, hope y'all have fun working on old outboards!!!



***[highlight]Oh, by the way, I cleaned the carburetor and connected it to the fuel tank and it started on the 2nd crank!!! It may look old but she will be a runner!!![/highlight]