Briggs 021032-0112E1-0405182A 34cc 4-Stroke "L-Head" engine. Has new head gasket, new coil, new gasket and diaphragm kit in Walbro Rotary carb, valves ground to .007" and .010" stem to tappet clearance. Compression 60psi bone-dry. 90-100psi with few drops oil. Engine ran 1 week ago but would not idle. It died and wont start since. Fuel introduced into spark plug hole OR carb intake immediately gets blown out through the crankcase breather tube when pull-starting. The breather tube connects to the end of the camshaft (which is hollow and made of nylon). This engine has an aluminum block. The air gap on the magneto is set at .010". Does anyone know why there is a no-start condition? The repair manual states the compression should be 50-60psi. I know Briggs doesn't normally list their compression ratings for their larger engines. Is the intake valve not seating properly? Thanks for any help!