The flywheel comes with 6 maggots on a kroller injin'

It is imperative that they are evenly spaced and polarity is correct.
If those 2 things are not done correctly, it will not put out full charge.
an electric clutch, lighting and batt-tree

recharge, uses a lot of the 15 amp available amperage.
A 2 part epoxy works well after judicious cleaning of the maggots & flywheel surface.
Spacing can be accomplished during glueing with rubber tubing or dowel rod.
large vice grips
lightly clamped can be used to secure during curing.
cracked magnets are un usable/junk.
Magnets can be removed from a like parts flywheel if undamaged.
Good luck!