ride the bike till it's out of gas, refill with GOOD gas, add a bottle of IsoHeet and ride that tank thru completely.....then refill with GOOD gas.
add some marine grade Stabil after that.
do not mix additives in the same tank of fuel.....always run them out of the tank, and let them do the job...then add fresh fuel....
oh, draining the float bowls occasionally helps also...