need help please! would be appreciated (nrg power 70cc - stage6 pro replica)

i have a nrg power 50cc now 70cc 05,
motoforce sport 70cc
stage 6 pro replica
jetted to 80
standard air filter and carb
3x3g + 3x3.5g rollers i think

when using it on full throttle it cut out was doing about 35-40 mph at around 9k rpm(need new rollers to stop this) then all of a sudden it cut out and wouldn't start need help theirs a minted spark, theirs compression from exhaust and also will there be any 2 stroke getting through if it doesn't start? would it be the piston rings by anychance? any help would be appreciated! and also what would be the best roller size once its going again for good acceleration and for a preferably okay speed?