Maximus, I don't really know for sure, since I added the synchrospark module and the Bowman ring at the same time. I suspect maybe 30:70, respectively. I have another unmodified Ryobi 31cc recently liberated from a 725r, and if I ever get around to it I'd like to mill the cylinder head base down a little to increase the CR. I'm convinced that I can then advance the ignition timing a little more with the synchrospark, use 93 Octane and get a few hundred RPMs out of it. I'll probably have to use a 20x8, as these Ryobis are not really meant to spin faster than 8000rpm or so.

The CH Ignition folks claim that you don't get any Hp gains from the CH conversion. I think they're too honest and conservative for their own good. They even recommend against using the Synchrospark module with these weedies. I bought one anyways and it works great! I believe so have several others.