Johnson wont idle; no power

A

adam22

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Joined

May 3, 2003

Messages

22

• Jun 16, 2003

• #1

Hello all. I have a 1972 Johnson 50HP hydro-electric shift. I finally got the shifting problems fixed, thanks for all your help. This thing would not idle, so I rebuilt the carbs(float,needle,gaskets,cleaned etc) I thought this would help. No change. I tried to adjust mixture screws. No change. I reset the ignition timing. No change. I replaced plugs (NGK). Now two outings later It has no power. I mean my trolling motor will go faster. It will only run at WOT and just barley moves the boat. When in neutral it seems to run okay(still no idle). Problem only when under a load. Fuel problem? Ignition probelm? Also checked fuel filter it was clean.<br /><br />Thanks

 

S

superman

Petty Officer 2nd Class

Joined

Aug 23, 2002

Messages

133

• Jun 16, 2003

• #2

Re: Johnson wont idle; no power

Will it rev any in neutral? How many rpms at WOT? Is your throttle linkage adjusted properly and is it advancing?

 

F

Fouled Plug

Ensign

Joined

Jun 29, 2001

Messages

935

• Jun 16, 2003

• #3

Re: Johnson wont idle; no power

What are your compression readings? Good spark on all plugs?

 

A

adam22

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Joined

May 3, 2003

Messages

22

• Jun 16, 2003

• #4

Re: Johnson wont idle; no power

It revs up fine in neutral. Linkage adjusted properly. Havent checked compression. One outing plety of power next outing no power. wont rev( in gear) over 1500-1800. If let of throttle any at all it dies.

 

J

jim dozier

Lieutenant Commander

Joined

Jan 8, 2003

Messages

1,970

• Jun 16, 2003

• #5

Re: Johnson wont idle; no power

Sounds like you're not running on all cylinders. Find out which one quit then we can find out why. Pull the plugs one at a time (or ground them one at a time) and see which one isn't doing anything.

 

A

adam22

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May 3, 2003

Messages

22

• Jun 16, 2003

• #6

Re: Johnson wont idle; no power

also timing is advancing properly

 

A

adam22

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Joined

May 3, 2003

Messages

22

• Jun 16, 2003

• #7

Re: Johnson wont idle; no power

if one cylider is not firing what are likely causes. coils? How to check? I will investigate when I get off work

 

J

jim dozier

Lieutenant Commander

Joined

Jan 8, 2003

Messages

1,970

• Jun 16, 2003

• #8

Re: Johnson wont idle; no power

Well the first thing to do if you find 1 cylinder not firing is to see if the spark is there. You should have a strong blue spark on the plug when its out and grounded to the engine. If not check the plug first then the rest of the ignition. It could also be dead even with spark due to fuel issues most likely requiring a carb rebuild.

 

A

adam22

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Joined

May 3, 2003

Messages

22

• Jun 20, 2003

• #9

Re: Johnson wont idle; no power

finally got to work on this thing again. Heres what i found: 180psi compression on both cylinders, bright blue spark on both cylinders. <br />I think i got fuel related problems. Local guy says wont idle b/c didnt clean carbs good enough. He says I should have soaked them.(i only sprayed aresol carb cleaner when i had them off) And now that I think about it, the no power thing didn't start happening till i rebuilt the carbs. What did I do wrong? Would float level cause this problem? What exactly should float setting be? Help please.

 

A

adam22

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Joined

May 3, 2003

Messages

22

• Jun 20, 2003

• #10

Re: Johnson wont idle; no power

Oh yeah. I also tried removing one plugwire at a time while it was running. When i did it ran much worse. Both plugs appear to be the same color upon removal. kind wet lookin.

 

A

adam22

Cadet

Joined

May 3, 2003

Messages

22

• Jun 20, 2003

• #11

Re: Johnson wont idle; no power

I think that I found the sudden loss of power. Small blockage in fuel inlet to top carb.(Iknow, i should have replaced that stupid fuel line when I did the carbs) Not letting enough fuel flow. But how about it not idleing.