Hello! I am reaching out for help. I have a fresh ground up build. It is a 1973 Peugeot 103. When I install the drive belt and tried to pedal it, it is almost impossible, and the clutch/fly wheel do not turn. The engine turns beautifully on its own as does the rear drive train. I have checked alignment, chain tension, installed the old pulley and belt all to no avail... Is the decompression lever important even with spark plug out? Thanks in advance for ANY advice!