Evinrude 35 sparks top cylinder only

[Bosunsmate]

Hi, I have a evinrude 1980 e35ecsm.Its only got spark on the top cylinder and i dont have a timing light to check if thats even sparking correctly as it really struggles to even get started on that one cylinder, although it is a decent spark.
The bottom has no spark.
Ive swapped coils and they both work. Ive checked the stator under the flywheel with a multimeter and i get the correct reading- 538 ohms and the rest are open which is apparently correct. The two wires to the trigger (sensor assy)i am getting no reading from, from what ive read im meant to get 10-20 ohmns.
Could a faulty trigger cause this sparking problem?
I dont have a meter that can read as "diode"scale which is what ive read i need to check the powerpack.
Thanks

 

[AlTn]

Re: Evinrude 35 sparks top cylinder only

couple of thoughts....you can get a dva adapter for your MM and use the tables at cdielectronics.com/troubleshooting to check the voltages going into the powerpack and those coming out to fully diagnose your problem, or consider the known : 1.spark on one cylinder 2. both coils work 3. in your ignition system, baring an internal break in a wire or a bare spot going to ground, nothing under the flywheel will fire only one of the 2 cylinders 4. that leaves the powerpack as the likely culprit

 

[tx1961whaler]

Re: Evinrude 35 sparks top cylinder only

^^
What he said. Plus eliminate the plug wires as the cause, unless you moved the plug wire with the coil.

 

[Will Bark]

Re: Evinrude 35 sparks top cylinder only

Dumb question, but have you swapped plugs to see if no spark follows the plug?

 

[Bosunsmate]

Re: Evinrude 35 sparks top cylinder only

Hi, thanks for every one of those advice above,
Yes the plug wire moved with the coil so they both checked out ok and i also checked both sparkplugs and they both unfortunately were good. Il try and get hold of a DVA adapter to check the voltage into and out of the powerpack or il see what the wrecker can offer me on a powerpack as having one spare wouldnt be too much hoarding if it wasnt the problem. Il write up here what happens. Thanks

 

[Bosunsmate]

Re: Evinrude 35 sparks top cylinder only

I replaced the powerpack with a borrowed proven working one and nothing happened at all. I replaced mine back on and nothing happened, the top cylinder now wasnt sparking too. So i removed the trigger. I cut the trigger wires near the base and tested the resistance from there, wow, the resistance suddenly went from .08 right up to 30ohmns. I checked the black and white wires back to the plug and the white wire was not reading. The coating all looked right so i felt along and there was a break in the internal wiring. I replaced the wiring and she now fires superbly on both cylinders with my original powerpack.
I guess there was not enough continuity wire to allow current through from the trigger for firing both cylinders from the one trigger. So AITn your point 3 was very adpt.
Cheers

 

[Bosunsmate]

Re: Evinrude 35 sparks top cylinder only

Follow up:Even though it was now sparking on both cylinders it was struggling and wouldnt accerelate although it started first time. So i put in a secondhand powerpack and it accelerated to full power no problems. The bad trigger signal must of degraded the powerpack overtime, ive heard of that happening- how one bad one can ruin the other

 

[AlTn]

Re: Evinrude 35 sparks top cylinder only

I believe the same can hold true for the external coils as well...one going hinky can cause the pp to act up as well

 

[Bosunsmate]

Re: Evinrude 35 sparks top cylinder only

Cheers, il keep an eye out for that,nothing worse than a problem cascade!