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No spark in cold climate

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Fishingfool001

New member
Hi all, new to the form. Recently bought a boat with an 1986 70hp Johnson 2 stroke. J70ELCD. First time taking her out motor started and ran perfectly fine. Got stuck toward the end of the day due to bad batteries . I replaced the batteries to 800 cca and good to go for the 2nd trip.

However before my 3rd trip the motor wouldn't fire at 5am, roughly 55 degrees out. Later that day I tried again, coughed, then started right up 85 degrees out.

Work done

New plugs+wires champion .03 gap
New Stator cdi
New power pack cdi
Clean carbs

To this day, months later I still have the same issue, motor won't start when in cold temperatures, no spark at all. But when it is warm outside she fires right up.

Flywheel spins like no other. I disconnected the rectifier still nothing, disconnected kill switch nada. Seems like no matter what I do she wont fire in the cold.

I run the engine with muffs at least once a week after work (80+ degrees out). But stumped when I get nothing in the colder mornings.

Any help would be greatly appreciated.
 
Have to ask-----Are you pushing the key in while cranking it over?----Are you giving it some throttle in neutral ?----Does spark jump a gap of 3/8" or more on a testing device ?
 
racerone said:
Have to ask-----Are you pushing the key in while cranking it over?----Are you giving it some throttle in neutral ?----Does spark jump a gap of 3/8" or more on a testing device ?
Click to expand...

Key is pushed, throttle is closed as the motor seems to start better that way. When spark is present it is strong, blue on the tester. But cold morning it is nonexistent.
 
I believe there is an easy fix for your motor.-----How do you know batteries are good.-----Have you load tested them or you assume they are good ?
 
racerone said:
I believe there is an easy fix for your motor.-----How do you know batteries are good.-----Have you load tested them or you assume they are good ?
Click to expand...

I just want it consistently to start. Got her fired up this morning roughly 60° out. Took about 5 tries but haven't had it start cold since the first day I got it. Batteries are a few months old just took them off trinkle charger. Voltage drop was minimal.

I also forgot to mention the crankshaft key was sheared so I replaced it 2 weeks ago. I fiddled around with the timer base/carb adjustments and held key in for 8~10 seconds before turning over to get it started this morning. Not sure why or if that had anything to do with her firing up. When its 80+ outside I dont need to push they key in, just one quick bump and she goes. However I do know 2 strokes can be difficult when cold. I'll keep testing to see if I can now get her going consistantly with key pushed in 8~10 seconds before turning her over.

Thanks and I will keep you guys posted!
 
Holding the key in for 8 to 10 seconds before cranking is a wasted effort !!------The electric primer is a valve that opens when you push the key in .----It is NOT a pump.----And no 2 strokes are not hard to start when it is cold outside.----An understanding of how your motor works and starts would help you a lot !!!-----They key is to be pushed in while cranking it over.
 
Back to the drawing board. Had spark for about 2 weeks started fine with muffs, hit the water this morning and she just wouldn't fire up. Should I just replace other components, coils and timer? Rectifier? Hitting nothing but blanks at this point. Could I possibly be losing a connection? Again 80+ outside temp I have no problem starting/running
 
What type of 2 stroke oil you using? The Ficht engines had the same problem with some aftermarket oils as it would thicken overnite and slow cranking RPM.. Sound like you need a battery or starter as testing on muffs vs in water with backpressure can effect cranking RPM ...
 
faztbullet said:
What type of 2 stroke oil you using? The Ficht engines had the same problem with some aftermarket oils as it would thicken overnite and slow cranking RPM.. Sound like you need a battery or starter as testing on muffs vs in water with backpressure can effect cranking RPM ...
Click to expand...

2 stroke oil is quick silver marine. This was first time in water in 2 weeks, was starting her in the drive way. Tried again cold start 60 out and fired right up after wiping off plugs, had oil on them, a few drops on each. Read that running with muff can cause this as I am not running as normal (in water) and the heat does get hot enough to burn off excess fuel/oil. Headed to the dock now. Last time in water she died as soon as I got in gear. Pulled flywheel and seen crankshaft key was sheared. Will be first time in water after that. Fingers crossed
 
That engine's ignition is created via the stator under the flywheel generating approximately 300 AC volts to the powerpack capacitor in order to energize the pack. The stator must be in good condition to generate that voltage plus the engine must have a ideal electric starting system as it needs to crank over at least 300 rpm.

I'm thinking the cold weather may play a part in having the starting rpm drop, hence the no spark condition?

Note that, unless you're the 98 lb weakling that Charles Atlas used to talk about on the back pages of certain comic books... Cranking that engine over manually with a starter cord. you'll by far exceed that 300 rpm mark for the short manual start period. Meaning.... If the electric starter won't generate the spark... that pull rope will... if the starting rpm is to blame.
 
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