Hi I have just rebuilt a speedfight 50cc moped, new crankshaft bearings seals etc new barrel and piston, when engine starts is revs to full capacity, I have checked the throttle cable and cleaned the jets in carb

Steve c, July 2010

i expect you have put the throttle slide in around the wrong way,take it out and check that the cut out at the bottom near the needle is facing the air filter when it in.also a carb being loose or a leaking gasket on the manifold will cause this problem.if the throttle has alot of play then the slides in the wring way.

adam bike doctor, July 2010

is slide in carb sitting right down? is tickover screw. screwed out enough.

rayb, July 2010