Any help very much appreciated. Problem starts and idles fairly smooth. Removed balance gears and have overhauled several cub cadets over 50 years. When you give it throttle it bucks and coughs and eventually stalls. Will run at idle fine. Replaced points, condenser, coil, and Plug. Rebuilt carb, replaced fuel filter removed and cleaned fuel tank. Checked wiring all good. No problems with rebuilds in the past. Checked lifter clearance on valves. At a loss only thing I can think of is crankshaft out of time with camshaft. Thought I was to smart to miss timing it right, but i'm at a loss for other ideas. What do you guy's think.