my son has a 2004 wrc206 50cc it keeps slowing down can u help?

it sounds as if it may be running lean (not enough fuel getting into the engine)have you had the main jet in the carb made bigger or replaced for a bigger one or even raised the position of the needle in the carb slide?as this will need to be done if you have a free flowing race pipe on it.i take it it has some light weight rollers fitted?

adam bike doctor
October 2006