It's unavoidable but a few things that help, my jet is mounted higher which helps for fall/winter fishing. Yes, depending on conditions, it will suck some air from time to time but I just trim down for a moment and keep her going. To deal with the leaves accumulation, I generally don't run the deep slow pools on rivers at slow/idle speed; I use the trolling motor to scout around instead. If I feel I'm losing any power, I stop in the first deep water or, pull over & shut down; then trim the motor up/down a few times to let the leaves fall off. Really a small window of time when this occurs but the better fishing makes it easy to accept. If you don't have power trim some jet boat guys use a small kiddie style, a cut handled plastic or spring tinned rakes to reach under and clean the grate.