Kicking back problems with my 72 Roadster

Put a few layers of pad or carpet under center stand - after you video the floor dance with a friend to enjoy it with too. Do note to see if full adv stops where intended one must rev up a bit over 5000, it ya brave enough to stand it or descend to lazy hobot habit and just diddle initial time so it just don't backfire on easy step over TDC starts any or barely does on swifter safer kick offs.

Don't forget kickback can be caused by lean conditions too.
My 850 usually starts easily first kick but one time it kicked back on me endlessly. Finally bump started it on a hill.
After riding a few blocks I noticed was running out of gas and had to open the reserve petcock.
I had been trying to start it with very low fuel pressure, hence lean conditions. Kicked back like a pissed-off mule.
I'm running PWK flatslides so no ticklers to flood carbs.

Are you running Amal carbs? Float levels OK?