Johnson Outboard 15 hp model 15R75C ignition problem

davio47

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I bought a Johnson 15hp model 15r75c this summer. It ran ok when I bought it but it bogged down and would start hard sometimes. I pulled the flywheel and installed new condensors, cam magneto and key because they were hammered. After I got it back together it will not start. It fired the first pull and that was it. Would not fire again. Points set to .020". Any ideas where to go from here? What did I miss?
 

Daviet

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Re: Johnson Outboard 15 hp model 15R75C ignition problem

Have you actually checked the spark? Maybe there is a wire under the flywheel that got shorted out when it started. Might not hurt to pull flywheel and recheck everything.
 

davio47

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Re: Johnson Outboard 15 hp model 15R75C ignition problem

Thanks for the advice DAVIET. I just got your response. I am going to pull the flywheel tomorrow and see if that may be the issue. I also opened the connector for the stop switch just to be sure that was not the problem. If you have any more advice it would be appreciative. I will let you know how I do. Do you know what the carb low speed adjustment is? I had to turn the needle valve in to take off the air intake when I cleaned out the gunk. What is a good starting point? One turn out?

Thanks
 

davio47

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Re: Johnson Outboard 15 hp model 15R75C ignition problem

Pulled the flywheel and checked the adjustment of the points as well as cleaned between points gap. Made note of two things. Firstly, one of the point adjustments was close to .024" instead of .020". Could this have caused my failure to start? Also secondly, the mag-assembly (not sure of the correct terminology) was not flush with the reference point. Which made it not close enough to the flywheel), I readjusted the spacing flush. After putting it back together the motor fired right up. Ran great. Thanks for your help.
 

bktheking

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Re: Johnson Outboard 15 hp model 15R75C ignition problem

Improperly adjusted points will change the spark timing, I'd say that cured it.
 

Rick.

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Re: Johnson Outboard 15 hp model 15R75C ignition problem

4 thou. on a plug would work but my experience with points is they need to be right on. I think you moved your coil and that would make a huge difference too. Not sure which one did the trick but who cares. Glad you got it going that easy. Rick.
 

Daviet

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Re: Johnson Outboard 15 hp model 15R75C ignition problem

Don't it make you feel good to get your motor running properly?
 

davio47

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Re: Johnson Outboard 15 hp model 15R75C ignition problem

It sure does feel good when you get it up and running. It can be frustrating.
 
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