Jeebus, listen, temps have little to nothing to do with engine break-in unless for some reason you’re running too hot. When an RC engine is in “break-in” mode, it won’t go, it’s actually pathetic. There’s a darn good reason the manufacturer doesn’t want you run at WOT during break-in.

Just follow the manufactures instructions for the break-in procedure before monkying with any carb settings.