well your compression reading comes from after the piston has completely sealed off inside the sleeve,, a bad crank seal wouldnt have any effect on compression since by time you are building compression the crank seal is closed off from the compressing part of the compression stroke..... if that makes sense?

with the spark firing outside the wire it sounds like a bad plug wire. could be a nick in it or something and is causing it to short out

a buddy's little brother had a KFX80... has a governor in the carb itself. Goes between the slide and throttle cap, looks like a piece of pipe and it keeps the throttle from opening all the way. Long story short we pulled it out one day and then ran the bike and it was wicked fun! But then it just died on us out of no where after we TOPPED it out////  after you pulled the restrictors out of this 50, how much did you rev it? Could have over revved it and blown the seals again is what im trying to get at,,