What is the best way to go about changing engine oil on a 01 sportsman 500 ho? I’ve been doing some reading online and I have heard about priming the oil system? What’s that about? You can drain the seperate tank (under left front tire fender) without a problem.. But the crankcase bolt underneath is a big issue I’ve heard.. My brother told me to not touch that bolt as he did a oil change on a 400 sportsman and said something about it losing pressure? Anyway, soon after the engine started knocking, which we all know what that means :/ anybody have any pointers?