Ah, Tim,
You conjure up warm memories of those uncomplicated days of that age of innocence we both remember and miss! I used to stop at the local garage fill the old Shell 2 gallon can with 5 star petrol (101 octane and a shed load of lead) then at the circuit mix up a race long quantity with R30 and go and have fun racing; safe in the knowledge that both fuel and oil were the best to be had. As a bonus, any petrol left over at the end of the day could then be poured into the transport tank to get you home. Mind you an old friend recently cautioned that; “nostalgia ain`t what it used to be”?
I`m not sure if it is of any help, but as a general rule when juggling the merits of Avgas or unleaded that, Avgas needs a high comp ratio to begin to work correctly, likes to run lean but hates ignition advance. Unleaded is the reverse, hates comp, loves running rich and needs a bit of ignition advance.
My good friend Steve Hall successfully compensated for both types of fuel when racing his 125 RS Honda, for unleaded Optimax we used a lower comp head insert, jacked up the jetting and, depending on the circuit and weather, tweeked the ignition advance. With Avgas the highest comp head insert was substituted, jetting came down, and a touch of ignition retard dialled in, dead reliable and won many races with both set ups, and he always swore by Castrol 747 oil. Your future post on fuel should be worth reading along with any other tales and photos you care to share with us. The transition from bike racer to jump jockey must have a tale there to tell.
Yours is only the second case of a fasciectomy I have come across, a school colleague of my wife, her husband has such surgery and I can remember his fingers were curled like claws prior to the procedure to remedy this. Knowing how invasive the operation is I can well imagine just how tricky and uncomfortable it must be for you to type out a post.
Cheers for now, Trevor