1975 Johnson 25 HP Not Running

racerone

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Both are NLA and were big $$ items.-----Time for some E-BAY shopping.-----Both are scrap in my opinion.
 

z.fields27

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Both are NLA and were big $$ items.-----Time for some E-BAY shopping.-----Both are scrap in my opinion.
In your opinion is that something that could have to do with it not running correctly? I found the cam magneto and currently searching for the flywheel.
 

racerone

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I would have no trouble finding a flywheel.-----Makes me wonder what else was done to this motor.
 

z.fields27

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I think I am going to be able to get one locally. I don’t know anything about the previous owner so I cant say for certain what was done before. I just wonder how big of a deal those parts make and if they are causing me the issues I am having.
I would have no trouble finding a flywheel.-----Makes me wonder what else was done to this motor.
 

saltchuckmatt

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I think I am going to be able to get one locally. I don’t know anything about the previous owner so I cant say for certain what was done before. I just wonder how big of a deal those parts make and if they are causing me the issues I am having.
Not sure anyone needs to answer that, common sense says "yes"

Finding the problem often is much harder than fixing it so I think you shall be rewarded soon.
 

racerone

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This kind of problem resulted from-( 1 ) too much torque on the nut---(2 ) trying to start a stubborn motor with impact gun or electric drill.-----Instead of trouble shooting , some folks just start using the wrong methods on a precision / fine motor !!!
 

saltchuckmatt

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This kind of problem resulted from-( 1 ) too much torque on the nut---(2 ) trying to start a stubborn motor with impact gun or electric drill.-----Instead of trouble shooting , some folks just start using the wrong methods on a precision / fine motor !!!
Yes, so it's probably time to tell him how to lap the new flywheel and mount it correctly so it doesn't happen again to him.
 

z.fields27

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Not sure anyone needs to answer that, common sense says "yes"

Finding the problem often is much harder than fixing it so I think you shall be rewarded soon.
I just am not sure of what that part does honestly other than open and close the points. This is the first engine of any kind that I have worked on so it has been a learning process.
 

z.fields27

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This kind of problem resulted from-( 1 ) too much torque on the nut---(2 ) trying to start a stubborn motor with impact gun or electric drill.-----Instead of trouble shooting , some folks just start using the wrong methods on a precision / fine motor !!!
I torqued the motor to 45 ft/lb as that is what I found in the manual. But it was cracked before I had ever put it back on. I can say with certainty that I didn’t try to start it with an impact but it could have happened before I bought it.
 

F_R

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Well those cracks are the result of somebody over torquing the nut. That motor is hopeless until you find a good flywheel
 

z.fields27

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I finally got the new parts in and installed. After everything was put back together I put the motor in a trashcan at the house and started it. It started on the 5th or 6th pull. All seemed well as it was idling nicely after I adjusted the lean rich knob. After I was satisfied with how it ran in the trashcan I decided it was time to make a trip to the river. I backed the boat in and fired it up. It ran for about 40 seconds and eventually started sneezing and stopped running. After that I could not for the life of me get the motor running again. I took it back to the house to check spark and compression which both looked good. The only thing that had seemed to change is that some fuel is leaking out of the carb. Not exactly sure what happened between starting it at the house and going to the river but will begin troubleshooting on the next warm day.
 

saltchuckmatt

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I finally got the new parts in and installed. After everything was put back together I put the motor in a trashcan at the house and started it. It started on the 5th or 6th pull. All seemed well as it was idling nicely after I adjusted the lean rich knob. After I was satisfied with how it ran in the trashcan I decided it was time to make a trip to the river. I backed the boat in and fired it up. It ran for about 40 seconds and eventually started sneezing and stopped running. After that I could not for the life of me get the motor running again. I took it back to the house to check spark and compression which both looked good. The only thing that had seemed to change is that some fuel is leaking out of the carb. Not exactly sure what happened between starting it at the house and going to the river but will begin troubleshooting on the next warm day.
Two different fuel tanks?
 

z.fields27

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Two different fuel tanks?
Same fuel tank but after I drove down the road I did notice that where the hose connects to the fuel tank has a leak. While running at the house that was not like that. Going to try a different hose when I get one.
 

saltchuckmatt

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Same fuel tank but after I drove down the road I did notice that where the hose connects to the fuel tank has a leak. While running at the house that was not like that. Going to try a different hose when I get one.
Running an inline fuel filter? Sounds fuel related. I'd pull that carb, clean it again and run on a portable fuel tank until you resolve the issue.
 
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