55hp johnson won't idle

Loose screw

Cadet
Joined
Jun 27, 2009
Messages
6
Hey all, my motor runs great at mid to high rpm but stalls at idle. when i push the electric choke it stays running for about 10 seconds then i have to push it again before it stalls out. i'm thinking fuel pump? is a kit a possible fix or a new pump? i'm stumped.
 

HybridMX6

Senior Chief Petty Officer
Joined
Oct 22, 2008
Messages
676
Re: 55hp johnson won't idle

Sounds more like a dirty low speed jet on the carbs than a faulty fuel pump. I'd give the carbs a good rebuild and clean, with new rebuild kits.
 

countvlad

Chief Petty Officer
Joined
Jun 29, 2009
Messages
439
Re: 55hp johnson won't idle

Sounds more like a dirty low speed jet on the carbs than a faulty fuel pump. I'd give the carbs a good rebuild and clean, with new rebuild kits.

i agree.. when you push the chock you bypass the carbs dumping fuel in the intake manifold... thats why you are runnig for a while...

decarb or rebuild the carbs if you cant remember last time they were done and you'll be back in business

if there was a problem with the fuel pump you would be able to run at WOT
 

HybridMX6

Senior Chief Petty Officer
Joined
Oct 22, 2008
Messages
676
Re: 55hp johnson won't idle

Well, you would NOT be able to...

I have a 2000 55hp 2 cylinder, and I need to do my carbs before taking it out again. I have the same problem as the O.P., it idles on 1 cylinder, but runs like a top once you get out of idle. I've been busy and putting it off.
 

Loose screw

Cadet
Joined
Jun 27, 2009
Messages
6
Re: 55hp johnson won't idle

Thanks for the info. i did a complete rebuild on the carbs in spring with new kits, replaced all fuel lines to no avail. The low speed jets were clean and i replaced the welsch plugs just to double check it was all clean. Could a bigger low speed jet help? i've almost got this thing running to perfection after having sat for 5 years. any other info greatly appreciated.
 

Loose screw

Cadet
Joined
Jun 27, 2009
Messages
6
Re: 55hp johnson won't idle

one more thing, would running a higher octane fuel help the situation?
 
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