first get rid of the airbox and get a aftermarket k&n filter. disconnect the oil pump by opening up the case and removing the oil pump gear...its very easy! and use pre-mix. you can also take out the spark arrester by unscrewing the baffel at the end of the pipe...take it out and cut off the back half of the arrester.....it looks like the tail end of a rocket...re-install. if the bike is a few years old you might need to clean out the exhaust port...they get clogged very easy....there is also a exhaust ring or gasket on the pipe...unscrew the pipe at the cyl.and you can see it on the pipe take it out with a screwdriver ...re install...i have tons of mods for the pw 50 if you have any ? feel free to email me at brandonhamrick2020@yahoo.com good luck !!!