No matter what I did, I could not start my engine last weekend.
Although BME 110 is a temperamental engine never have had starting issues.

Since I have 2 BME 110 engines at home (one mounted on my Edge the other one in stand by to be used for another project):

1) Swapped carburetors, to rule out any carburetor issue, same results.
2) Swapped batteries, to rule out a battery issue.

Once in the shop I removed the spark plugs and tested the spark to check the ignition. It seemed to work OK however after flipping the propeller to verify the timing, after couple of flips both spark plugs stop giving up!

This fact paid my attention since this engine flame out apparently due to a lose tank more than 6 months ago.
However the sparkles event woke up some suspicious, then I started troubleshooting that seemingly lack of spark.

a) I started by swapping the ignition unit, after flipping the propeller couple of times I did not observe any spark.
b) Then I swapped the hall sensor, same results.
3) Then I tested the ignition on the other engine and this one seemed to work fine.
At that point the only think left was the small permanent magnet attached to the hub of the engine.
One thing I noticed is that the magnet could not hold a small needle pin. While the other engine’s magnet could easily hold the needle (check the attached picture).

Clearly the failing engine has mounted a weaker magnet.
I am not sure if these observations make sense to you guys that have seen more gas engine failures.

A possible theory:

To me the weaker magnet induces a smaller electrical impulse into the hall sensor, (Faraday´s law induction E=dB/dt) otherwise will not induce any pulse at all, therefore without no input pulse or too week amplitude, it will not trigger the electronics inside the electronic ignition box. Could this explain why I could not start this engine, having everything else ruled out?

Would that be a valid conclusion?
Has anyone else seen such problem before?
Do these small magnets “decay” or lose magnetism?
Can this explain the spontaneous engine flameouts that I have seen on this engine?

I am going to perform additional tests, I am kind of reluctant to accept the above outcome, however the evidence is telling me that there is not other why to explain this problem.