New Head on Predator....SO MUCH easier to start?

Hey folks,We just completed the head swap on our modded HF predator. It is SO much easier to pull start. Any thoughts why?

PREVIOUSLY- 14cc clone head (self ported and polished...first time), Mod 2 Cam, Honda .625 carb, velocity stack, Header, SS valves, 1.3 rocker intake, billet rod and flywheel, stock dished head, .2 in hole. /1 gasket

NOW- 18cc Honda Head (NR racing ported and polished 27 and 24 valves, milled 0.50)...everything else is same

Before the swap, the engine was hard to pull start (Im a pretty strong guy), would occasionally snap back and destroy my hand (my 150 lb athletic son was unable to pull hard enough to start)

Now....when I pull starter and find compression, it feels much less....actually really easy to start. No dyno, so no objective measure of power. Butt dyno feels the same or slightly more powerful.

Any thoughts on why this is so?????
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I'am with Trinik 7597 those to heads are real close an 18cc milled 50 is real close to 14 and with a dished piston your compression probably 12.1 or so . You had to have your valves set wrong . I have a clone with a 18cc head and it right at 13.6 to 1 and it pulls no problem , and my valves are set right .