got some questions about a 01 pw 50. i bought the bike used for my 4 yr old son, and it didn't have the throttle screw. i bought one and put it in and the throttle wouldn't move at all. i ran it in a good way first and the throttle wouldn't budge i ran it out maybe 3 or 4 threads in and still nothing. is there something im missing. is there another way to restrict the throttle. or am i gonna have to get a new throttle.