Magnets, 2 cycle and 4 cycle
Are you talking 2 cycle in both cases?
A 6 cylindere 2 cycle engine will fire 6 times per revolution to be compatable with the 2 cycle operation. Thus there are 12 magnets total or 2 magnets per cylindere on the flywheel to create the low voltage in the 2 magnet loop as the flywheel passes the metal poles.
The same for a 3 cylindere 2 cycle engine, it fires 3 times per revolution.and requires 2 magnets per cylindere thus 6 magnets total.
If the 6 cylindere is a 4 cycle engine each cylindere will fire once evey other revolution thus 3 fires per revolution.
The number of magnets on the flywheel is necessary for each case.