When "hot" there is no need really to prime. Fuel pump "ON" for 5 secs - do NOT set mixture to "RICH" - fuel pump OFF.
That is interesting, I've got to try this!
What exactly is supposed to happen when the pump is switched on while mixture is left at idle cutoff?
From what I've learned reading the docs linked to in this very thread, the fuel pressure would build up against the closed valve of the mixture in idle cut off, hence no fuel at all would be delivered to the manifold, right?
Our school operates two S-300C, one of them has the high energy starter installed, fires up easier. The other one my buddy and me were flying an hour into the mountains, in current very hot days. We paid landing fee and refueled a bit and when trying to fire it up again it resisted. We tried various things for a minute or two, only to be suprised by sudden starting. We do not know exactly which sequence of actions it liked, but we certainly never did do your "prime at idle cutoff" trick.
So what's the "prime at idle cutoff" do, internally?