Now that you have it firmly mounted
try setting the timing just past TDC.
You probably won’t be able to reach
this point by bouncing it off
compression so pull it through instead.
This should give you a bigger “kick”
when the plug fires to keep it going.
When it kicked back and hurt your
hand that would seem to indicate you
have found the correct fuel – air mixture.
Once you get it running and dialed in
you may have more success starting it
by bouncing it off compression.
Tubs
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.