2hp briggs.ran.stopped.wont start.

[dmartin1]

i have a 2hp briggs stratton on one of the few mii bikes/gocarts i have.

it was running fine idling,i gave it a bit of gas,let it idle,,,and gave it quite bit more gas and it bogged out and died.i was also messin with the jet finding the ahppy spot.

took the ehad off,valves arent stuck,rings are good,brand new inside of the cylinder,pistons clean and ice,
im getting spark
good compression.
it was ran on 2 stroke gas for 5 minutes(my brother).

'and it backfires through the carbuerator sometimes.whats wrong?
yes the coil and mag pick up magnet are clean
all good gaskets and seals