Cox .049 1969 Dune Buggy Engine

Does anybody know what type of engine cylinder was used on this engine? I.E. cylinder number,1 or 2 ports.I rebuilt a 1969-1970 engine from the ground up but the performance is poor (Hard to start,really poor/short run time,about 1 or 2 minutes Max.) but when engine runs it sounds good & peaks out with the needle valve adjustments.

It should have a single bypass cylinder with sub-piston induction, it may have a #7 stamped on it or it may have nothing stamped. It may also have a throttle ring on the cylinder. The engine shown is out of a Baja Bug, but the Baja Bug and the dune buggy both had the same frame. The cylinder is off that engine. Are you running the engine in the car or out of the car? You don't want to lean it out too much when its not in the car (just about to engage the wheels). If it doesn't have enough force on it when its running, it could turn too fast and possibly throw the rod, break the crankshaft, mess up the piston... it could also overheat. Try to make the mixture richer, turn the needle out a 3/4 of a turn or so once you have it at the peak performance. Check the fuel pick up tube inside the tank, it may not be in the right position to pick up all the fuel from the bottom of the tank.