Can anyone tell me what type of main jets are used in the Yamaha PW50? I helped a friend of mine get one for his boy and I'm trying to get it tuned up properly for him. I believe that it uses a 70 main jet stock and I'd like to order the next size or two smaller to see if we can get it to run a bit better, but I'd rather not rip it apart just to see what size and type of main jets it contains. Can anyone help?