Hi..
If you lose the original setting of the compression screw, prime the engines then flick to start, meanwhile with the free hand screwing IN compression 1/8 turn between flicks until the engine fires. You are then within 1/4 turn either way of the cold start setting.
Hot re-starts are the same procedure, BUT from the last best hot running setting (max. speed under load) it will be found necessary to UNSCREW the compression lever 1/4 to 1/2 turn first. This will become unnecessary when the engine is fully run in, and a really good flick is learnt.
COLD START = HOT RUNNING SETTING PLUS 1/4 TO 3/4 TURN IN OF COMP. SCREW.
HOT RE-START = HOT RUNNING SETTING LESS 1/4 TO 1/2 TURN OUT OF COMP. SCREW.
Also, you choke your engine by covering the venturi and flipping the prop a couple of times, right?
No, do not prime to much, can cause more compression and difficult to start and get damaged wristpin/con.rod. Read above as i wrote.
Jens Eirik