30 hp johnson idle problems

jpowell_2010

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Joined
Sep 29, 2011
Messages
12
Last weekend i took my boat out and it was doing fine idle was good throttle responce was on the dot. Well this weekend i took it out and when i took it off the trailor it wasn't idling very well but i figured its a 2 stroke its getting cold out not a big deal. well long story short every time i put it in nuetral it cuts off. When i give it throttle it runs fine and has great responce. I checked the plugs and they are good (only bout a month old) So i'm thinking its something with the carb. Does anyone know if it could be simple as cleaning the carb or more complicated?
 

whiskerchasin

Seaman Apprentice
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Jul 25, 2011
Messages
45
Re: 30 hp johnson idle problems

Yes i think it could be simple as cleaning the carb, probably something stuck in the low-speed jet. Keep in mind i'm no expert and you should wait until one of them chimes in. They may need the model# to know what your working on. GL
 

kfa4303

Banned
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Sep 17, 2010
Messages
6,094
Re: 30 hp johnson idle problems

Hi jpowell. I think you may need to clean/rebuild the carb. It's not a difficult job and a new carb kit is only about $25. Unfortunately, the ethanol in modern gas is casing major headaches for carbureted motors by leaving behind varnish-like deposits in the passageways. As a result, they require fairly routine cleaning and inspection to make sure the passages remain clean and open as even a slightly blockage can impair performance. A good can of carb cleaner and a rebuild kit should do the trick. You may also need a new, plastic carb float, if you still have the old cork style float. The cork can breakdown over time and also clog the passages.

Let us know the year and model of your engine and we can direct you to the correct carb kit and instructions.
 

jpowell_2010

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Sep 29, 2011
Messages
12
Re: 30 hp johnson idle problems

My engines a 1994 johnson 30 horse power. It seems the previous owner had installed a carb kit recently on it. (i'm no expert but it does seem to have new gaskets etc.). If i'm gonna be taking the carb apart i might as well put a new kit on it while i'm at it especially if its only $25 or so. Yeah the ethanol is a killer i run high grade gas in it and always run it on the muffs after each run and unplug the fuel line untill it burns all the fuel i had hoped that would be enough to keep it clean do you think that could be my problem letting the fuel run out of the carb?
 

kfa4303

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Sep 17, 2010
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6,094
Re: 30 hp johnson idle problems

I don't think running the gas out would hurt it. I'm not sure how to avoid the dreaded "ethanol varnish" without using fuel additives like Sta-bil and Sea foam each and every time you get a tank of gas :/
 

recon c32

Cadet
Joined
Apr 16, 2011
Messages
13
Re: 30 hp johnson idle problems

Check the foam in the cover I had same problem fough it for 2 years cleaning carb after each use old timer told me to remove foam been running for 4 yrs no problems Gunk Engine cleaner will bring it right along with glue
 

jpowell_2010

Cadet
Joined
Sep 29, 2011
Messages
12
Re: 30 hp johnson idle problems

That is a great idea i just thought bout that because i've found some of the foam on the engine pan like it had fell off. so the Callen will me alright without that foam?
 

jpowell_2010

Cadet
Joined
Sep 29, 2011
Messages
12
Re: 30 hp johnson idle problems

I tell you what if anyone has a small johnson thats carbed i can fix it if it wont idle. Cheap probably got it laying around your garage shed whatever. Theres a piece of the carb that gets pushed by something under the fly wheel. (sorry i'm no boat michanic don't know correct terms) but if you put a little electrical tape on that piece and pretty much advance the carb. it idles right where it should. I can put it in gear just fine man easy quick fix if your on a budget. Plus its about to get cold in south east georgia and then i'll take the carb apart but for now i got her running good.
 
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