Moped Army

Hello,
I've been told kitting an engine burns them up faster. I'm assuming, then, that this must be true with larger carbs/pipes as well since they make the engine work harder...? Can anyone shed some insight? Should I expect to get a considerably less amount of engine life w/ lets say a kit and pipe? Are there certain upgrades that are less demonic? This is a 95' Targa with something like 4k kiloms