Tuning an old Johnson 5 horse

richard1

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Sep 16, 2002
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Thanks to all the help we got from the forum, we got a new coil at NAPA auto and put it in the motor. It runs for just a minute or two and then quits. Is there some secret to adjusting this motor that we do not know. It sounds good when it does start, just doesn't keep going.<br />**** Jonas<br />RichRchrd1@aol.com
 

superman

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Aug 23, 2002
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133
Re: Tuning an old Johnson 5 horse

When it shuts down do you still have spark? Is the plug wet?
 

JB

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Re: Tuning an old Johnson 5 horse

Ahoy, Jonas.<br /><br />It is not likely to be an adjustment. I think your engine is using up the gas in the carb bowl and running out.<br /><br />Your #1 suspect is the fuel pump. Disconnect the gas line that goes into the carb and stick it into a bottle. Spin the engine over and see if you get strong spurts of gas from the pump. <br /><br />No spurts or weak spurts? Get an inexpensive fuel pump overhaul kit and redo the pump.<br /><br />Good luck. :)
 

richard1

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Sep 16, 2002
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Re: Tuning an old Johnson 5 horse

Thank you for the suggestions on our old Johnson to get it running. I don't know how to reply to the individuals on the posts. I hope you see this and please any other suggestions are welcome.<br />**** Jonas
 

richard1

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Re: Tuning an old Johnson 5 horse

In answer to the question, Is the spark plugs wet, yes they were wet. But, it ran only a few seconds to a minute and then got tired of playing that game.<br />**** Jonas
 

JB

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Re: Tuning an old Johnson 5 horse

Howdy.<br /><br />In answer to your added question on another post, Start out with the low speed needle 1-1/2 turns out from the seat, and the high speed jet about 1 turn out.<br /><br />It would not be a good idea to fiddle with the mixture settings until you get it to keep fuel in the carb. As I suggested above, it is not likely to be a setting; trying to adjust away a failure in fuel supply will only make things worse.<br /><br />Good luck. :)
 

markjewell

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Jul 2, 2002
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Re: Tuning an old Johnson 5 horse

I agree with JB on this. (even though his delivery can be a little tough at times ha-ha).<br />If when you take the fuel line off the carb, and you pull the engine through, and you are getting good spurts of fuel, I would suspect that the carb should be taken apart and cleaned. It is not a hard job. It could be that the needle is sticking in the seat, or you have a bunch of guck and varnish in the bottom of the fuel bowl. All your fuel for your motor is really sucked into the main jet from the bottom of this fuel bowl.<br />If the motors sit around, the old fuel congeals and turns into a varnish type substance, and therefore can not be sucked into the motor.<br />Not every piece of the carb has to come apart!!<br />Get yourself a good parts manual and service manual, along with a $15 carb kit (has new gaskets and new needle and seat),a can of spray carb cleaner,and a couple of cold cans of beer.<br />I know that you can do it!!<br />(How'd I do JB????)!!!
 

JB

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Re: Tuning an old Johnson 5 horse

Sounds good to me Mark. :)
 
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