76 johnson 25hp: no spark at points?

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welder

Cadet
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Jul 18, 2003
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6
76 johnson 25hp: no spark at points?

Mod.# 25RL76E, Ser.# E4446271 , 76 Johnson Seahorse. I have had this motor 3 months ran great, then just died out in the water and havent been able to start it since. Had earlier problems not getting spark to coils,.. bad kill switch. I have key or pull start and my starter motor turns over good, good spark at plugs,good gas flow,(50:1)mix. I've had a couple of backfires and that is it. Any info or input would be great. Thanks
 
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Paul Moir

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Nov 5, 2002
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6,847
Re: 76 johnson 25hp: no spark at points?

Re: 76 johnson 25hp: no spark at points?

Check to see if the flywheel key sheared. If that flywheel wasn't tourqued to specs, it'll turn on the shaft and put timing way out. That'll cause the engine to backfire only.
 
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welder

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Jul 18, 2003
Messages
6
Re: 76 johnson 25hp: no spark at points?

Re: 76 johnson 25hp: no spark at points?

Thanks Paul, I am checking pin, points will not stay gapped correctly, after motor backfires. I set points at 0.20, boat has battery ignition, copied truoble shooting section out of manual and hoping I can atleast get it narrowed down to one or two things. Thanks again
 
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welder

Cadet
Joined
Jul 18, 2003
Messages
6
Re: 76 johnson 25hp: no spark at points?

Re: 76 johnson 25hp: no spark at points?

I know this may sound dumb, but how do you tell if the flywheel key is sheared? I'm not sure how it looked before and it looks ok now, but I have some fine metal dust under the flywheel. Any help would be appreciated.
 
OBJ

OBJ

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Joined
Dec 27, 2002
Messages
10,161
Re: 76 johnson 25hp: no spark at points?

Re: 76 johnson 25hp: no spark at points?

Hi welder...if the flywheel key has sheard, you will find two pieces under the flywheel. One part in the flywheel key groove and the other in the key slot in the crankshaft. If may also only be partially sheared also. But which ever the case, it will need replaced.
 
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