i own a 03' 400 with the air cooled engine and had never had a problem with it overheating, ya the fan's come on but its meant to keep the temp in check. After i ride it hard and turn the machine off, i turn the key to let the fan run for 2-3 min or until it shuts off, doesnt drain the battery and cools it down a bit. My 650 is liquid cooled and ive never had a problem with that either, i guess being air cooled saves u some weight though.