Most weedies are set up by power mad fliers and are timed at full advance 30 deg BTDC. That is why there is no improvemnt with the SS at full throttle.
Ive run 4.2 Sachs with fixed timing @ 30 deg BTDC. Its not real bad but you have to be firm about starting it or you will get bit. But the weedies size and low comp make it much safer. If you have a timid flip when trying to start an engine or worried then by all means add an Syncro to your weedie.
TKG
CH Electronics
Yes I do know a bit about weedies