No firing issues

Dear all,

I need your precious advice. Took the engine out of winterization (OceanRunner v4, 90hp 1998, BJ90SLECM), and both bottom cylinders have no spark. Replaced the allegedly faulty powerpack with a good one, and still the problem persists on two bottom cylinders.

Changed the optical eye with a new one (original not Sierra blue) on my engine, and get no spark at all most of the times. Sometimes I get spark on all 4 cylinders.

Battery is fully charged and engine rotates clockwise.

Took the allegedly faulty powerpack on another good working engine same specs as mine, and cylinder 1 is not firing. Bottom cylinders fire on that engine.

Any advice on what might be wrong with my engine?
And can you understand whether the allegedly faulty power pack is faulty or not?

Thanks,
George

PS: I am checking the spark with grounded QL78YC spark plugs gapped at 0.3, I dont have a tool.

Pull the flywheel off. Check the wires coming from the stator. Lots of times the clamp that holds the wires down. The bolt comes loose. And the harness starts touching the flywheel.

Hello thanks for the reply. I removed the flywheel and everything looked fine. I did the following tests (thanks to Youtube):

1. Removed the black/yellow wire from the powerpack. No spark.
2. Removed the port side wire connector to the power pack. No spark.
3. I tested the resistance an all 4 coils. Within specs (at 275Ohms +/- 50)
4. I cleaned all the grounds I could see by eye.

Any more advice?

Check the resistance of the stator and the trigger coils also

Hello, I checked the resistance of the stator and coils. All within specs, as found here:

https://www.go2marine.com/productcenters/electrical/johnson-evinrude-1995-2006.pdf

I reassembled the engine quite dissapointed, and then it worked. Cant figure out what has been happening. I think it is magic. Or maybe it was because at the same time I cleaned connections to ground, etc. Thanks for the guidance.

Only way both bottom cylinders cannot fire is bad coil assy or ground to that coil assy..

Indeed this sounds right. But I swapped bottom and up coil assembly to verify that... It still gave me no power on the bottom ones...