On a weedie there is no improvment at full throttle with a SS unit over a CH unit with fixed timing. Start up is about the same and there is a few hundred RPM diff at idle( the SS will idle slow and smoother)
Reason?? most weedies have one ring and poor compression at cranking/slow speeds, so there is little kick back.
Two rings and 35CC is about the cross over point where you DO NEED the Syncro or a mech timing control