RE: stihl ms 250
moreoctane
put electronic ignition on it. saves weight, performs better,
Iam not familiar with this engine what size is it what was its former job blower ,weed trimmer etc.
apparently the magneto is not mounted to the engine. a mount must be fabricated to hold the magneto
near the flywheel to generate a spark , it would have to be stable and solid unafected by vibrations and G-loadand it would have to be adjustable to time the ignition . it would be easyer to put a cd ignition on it , lighter and better performing too
however it would be more expensive.