Johnson 225 Rough Idle

R

R.A. Young

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Dec 18, 2006
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I have 1989 225 Johnson V-6 model # J225TXCED. We have done extensive work on this engine this year.and have replaced the stator, charging rectifier, water pump, vacuum switch, primer solenoid and rebuilt the carburatorsas per specified by the OMC repair manuals. As you come off plane to idle speed the engine seems to struggle to idle as if it was running rich and the engine will spit and the warning horn will chirp one (1) time? The motor will start right back up, but |you have to use the cold start lever to clear the carb's ? Then it idles OK for a short time? Everything seems to be working ok at higher speeds?
 
C

Cricket Too

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Re: Johnson 225 Rough Idle

I'd guess that it's running lean if it's spitting like that at idle, especially enough to cause it to stall or the timing is off.

If you have to use your fast idle lever when the engine is warm, then you may have a timing problem. That fast idle lever just advances the timing for cold starts, slightly opens the throttle plates.

Is it cooling properly?
 
R

R.A. Young

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Re: Johnson 225 Rough Idle

Yes.... It's cooling properly? Checked timing and it was dead on as per spec by the OMC shop manual?
 
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R.A. Young

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Re: Johnson 225 Rough Idle

I keep thinking it could be a clogged pluse limting fitting, or a bad fuel pump?
 
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ezeke

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Re: Johnson 225 Rough Idle

Or you could have a disfunctioning shift interrupt switch.
 
C

Cricket Too

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Re: Johnson 225 Rough Idle

Yeah the rough/low idle could be caused by the shift interupt switch, but wouldn't that only occur when it was shifted into Neutral.

I took this as just coming off plane to a slow speed in gear. Plus the swicth wouldn't cause the spitting.
 
R

R.A. Young

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Re: Johnson 225 Rough Idle

I went back and rechecked my work only to find the carbs mounting bolts had backed off and the carb's were not tight to spec on the throttle body. I have no idea why the came loose. I place a lock washer on the mounting bolts and tighten back to spec. We will test run today for another acid test to see if my problems go away?

Thanks for the help.........
 
Oregondunes

Oregondunes

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Jul 9, 2009
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Re: Johnson 225 Rough Idle

Im having the same issue right now. My carbs are all tight to spec, new fuel lines, timing was perfect. Then after a couple of free revs on the clam shell in the driveway it started spitting and sputtering and wouldnt run off the cold start.

Took the electrical all apart and found EVERY magnet on the flywheel had come loose. I dont know this thing even ran at all.
 
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