Force 125 flywheel magnets

[boatsmitty]

Has anyone had problems with these magnets? A mechanic replaced my flywheel with a used one about two years ago and the boat runs, but is ragged in the mid-rpm range. It is doesn't like to idle in gear. I have to be quick to accelerate once put into gear. I cleaned carbs, checked coils, replaced fuel pump diaphram. Then I pulled flywheel and noticed that the magnets are in a strip around the inside of the flywheel. There is a gap at the magnetic strip ends. The strip end is easy to slide up and will probably slide out of the flywheel. I thought this might affect the ignition timing. The old flywheel looks much the same except the strip is thinner. How do I know if the flywheel magnets are buggered.