carbs. gurtner is the stock carb that comes on the mobys. dellorto is an infinitely better carb. but the truth is that the cadys arent really speed demons, i'm sure you could make them awesome, but it might be more work than its worth. honestly, clean the shit out of your carb and make sure the gaskets are all good. if it isnt the carb, get a new petcock.
dont get me wrong, i love my cady. it's fun and cute as hell, but if you are looking for any kind of performance get a 50v and work on that bastard.