Bike keeps fowling plugs could it be the

It could be a rich mixture. look on the carb and you'll see a screw ( straight head ) this is the air mixture screw. try turning it out a quarter of a turn and see how it runs. out = more air in = more petrol causing black soot on plug. you will notice lots of smoke out of the back if your oil mixture is too high. 32/1 will be fine and change your spark plug instead of cleaning old one

Usually 2 strokes foul plugs when the oil is two strong in my old bike i mixed the gas 40:1 try that and if it dosent work i would take it to your nearest dealer and get them to check it out