Decompressor

Did a search and cant find what im looking for really. My bike starts when cold ..still a little hard but it starts, but WILL NOT start hen hot. So i just broke it down again, all clearances in check, timing on according to flywheel, cam sprocket and the crank on right side. I stuck a .25 in the decompressor and it slid in fine, On the loose side, should I bring it down to like a .21?

My question is should i tighten it or loosen it to make it easier to start when cold and more importantly hot.


EDIT: Sorry just realized i posted this in the Lounge instead of Engine section, really sorry if a mod can move this thatd be appreciated.