well first off i was told it was either or.....Magneto, or CDI box....how do you tell which one to replace...how does either go bad...and what do they do for the bike?.....my bike has a good spark, weak compression...6-10 hrs on the piston, and its carb was recently cleaned...i dont know much about this bike as it was a christmas present and since then we split up so im stuck with an easily fixed bike....anyone out there willin help??
1998 YZ 80