1986 60 hp Johnson vapour lock?

[ShoestringMariner]

I recently freshened up a 60 hp Evinrude for my brother. Three cylinder 1986 model.
A few times lately it has refused to start. In both cases it took removing the spark plug to check for spark while cranking that actually caused the motor to fire. In both cases the motor would not fire cough or a sputter at all on either choke or manual fast idle.

The fuel line was full. Primer bulb rockhard. Disconnecting caused fuel to spray out of the coupler connected to the hose. It happened once on a coldstart and happened once after use and one and a half hour cool down. Both times identical process. Both times removing one spark plug caused it to immediately fire. (more specifically fire elsewhere in the motor. Not fire coming out of the hole) but exhaust smoke was detected coming out the top hole. Starting attempted with motor in the water. Not on muffs

This was a motor I picked up last fall. I replaced all the fuel lines with standard correct ID fuel line from an automotive parts house. I used Evinrude fuel zip ties. These were not formed OEM hose replacements. Re-built the carbs with full kits.
What we find really odd is that nothing works until one spark plug is pulled. Then it fires almost as if the motor cannot breathe. Like the fuel air mixture isn’t getting in until we open it up. Do two-stroke suffer vapor locks of sorts in this case? Stuck reed valves? Fuel pump issue? Crank case leak?

I lent this motor to my brother. I’d really like to get it sorted out for him so he can get the rest of the season in.
Thanks in advance

 

[racerone]

Stop guessing.-----Load test your battery---FREE service in most places.------Take starter apart for inspection and ohm test on armature.-----I say motor is not turning fast enough for magneto to be happy !!!

 

[ShoestringMariner]

Stop guessing.-----Load test your battery---FREE service in most places.------Take starter apart for inspection and ohm test on armature.-----I say motor is not turning fast enough for magneto to be happy !!!

OK cool so when we pull the plug it’s spins faster causing the spark to light up?

 

[oldboat1]

Yes. Likely battery and/or starter. But use an adjustable open air tester -- should see a half inch (likely more). This is a test of the ignition system

 

[ShoestringMariner]

Thanks guys, will check it out. But One thing that bothers me about this though is that if it was a spark issue, would the motor not flood out terribly? There was none of that. No fuel smell, wet plug or gas slick in the lake. No heavy smoke or rough running when it did fire up.

it’s as if fuel did not flow until one plug came out. And cranking speed IIRC was fine. We cranked it over for some time. I will check spark, but I do feel it was like the fuel wasn’t coming through.

 

[racerone]

Keep the folks informed with your guesses.----Is your electric primer valve working as designed ??-----Pushing the key in while cranking it over ??

 

[ShoestringMariner]

Keep the folks informed with your guesses.----Is your electric primer valve working as designed ??-----Pushing the key in while cranking it over ??

Not guessing. Motor is 30 mins away. Dropping my spark tester off for my brother to try. Yes, pushing key continually. No fire with or without.
I wasn’t sold on it being electrical due to low starting rpm and lack of flooding. So starting solenoid sounds very logical and will get looked at. Thanks for suggesting it