drain the carburettor off by undoing the small screw right at the bottom on the side and then lt it drain right off,make sure you turn the fuel off b4 you drain it though.onces the carb is empty do the screw back up turn the fuel back on a nd try again.the plug may also have gotten fouled by the old fuel so i would suggest replacing it too.also the py is defiately a 4 stroke engine so no oil in the petrol just in the engine but dont overfill it
adam b doc
July 2012