I had the screw on the carb choke valve come loose and go through engine. Have dis-assembled engine and checked and cleaned valves. Lined up dots on crankshaft ring gear and cam gear at top dead center; engine sounds like it is firing on intake. What is the proper procedure for aligning the valve cam gear with the crankshaft gear?

Sounds like you assembles your crank 180 degrees off. Lossen the cam gear and rotate one full turn, match dots and tighten.