Another stalling motor

[Q-Ball]

I just bought a used '97 or '98 Johnson 55 HP that had previously been having problems idling and was told that the gear case was iffy. I disassembled the carbs, didn't find any gunk and the orifices looked like they were all open and cleaned the fuel filter. It ran great until the gearcase failed after about 15 hours of use. Switched lower units from another 55 HP that was laying around and now it is starting to stall when slowing down about half the time, starts up after priming. I don't think it is the hose or the external tanks that is causing it to stall since I used them with another motor without any problems, although the inline filter has some particles that I can see. I do have a couple manuals but they are for different model 55s and I'm not too tech savvy about outboard motors nor are there any shops that I can bring it in to for servicing, nearest one is 2 airline hops away.
Any ideas on what would be causing it to stall and what troubleshooting steps should I perform to track down the cause of the stalling and fixing it?

 

[fireman57]

Re: Another stalling motor

Welcome to iboats. Just taking the carbs apart and looking at them doesn't clean the bits of varnish and junk that is in them. You can order rebuild kits right here and do them right. Take them apart and soak them overnight is a good carb cleaner. Blow out every orafice you can find with compressed air. There are little round (Maybe 1/4 inch) aluminum tabs that you need to pull out and clean behind. The rebuild kit should have new ones in it to punch back in. Also make sure you have the correct champion plugs in it and they are in good shape.

 

[tashasdaddy]

Re: Another stalling motor

and you need this tool to get the jets out, can be made from quailty screw driver. have you checked compression. http://i155.photobucket.com/albums/s311/frankr_photos/FixedJetScrewdriver2.jpg?t=1177353186

 

[jtexas]

Re: Another stalling motor

tashasdad,
I've been making do by cleaning the jets in place, but it'd be great to have a tool like that...if you get some time, I wonder if you'd care to elaborate on your fabrication methods...what kind of cutting tools, how you get a precise measurement, that sorta thing...

thanks,

 

[tashasdaddy]

Re: Another stalling motor

i got this from 'imported FR' he might be able to tell you, i would just put the screw driver in a vise, and take a file and give it a shot. you can also get them from the dealer. i shop has them $18.00 part number 317002.

 

[F_R]

Re: Another stalling motor

Take a file and give it a shot. That about says it all. If you screw it up, cut it off and start over. The two blue ones are factory made. I think I made the stubby one. A micrometer or dial caliper will measure to the .001" Or if you have a spare jet it will serve as a guage. Or file till it fits.

 

[Q-Ball]

Re: Another stalling motor

Thank you fireman57,

I will give the carbs a cleaning as you suggested.

I just looked in the manual for a different model 55 and it listed it's spark plug recommendation as QL78YC, I've been using L78V plugs. Would using non-recommended plugs have an effect on the motors performance?

In the mean time can I use the carbs from an '97 Evinrude 55 on my Johnson?

tashasdaddy,

I don't have a compression gauge, but it seems to have good compression.