OK, here is where I have to stuff my hands in my pockets and kick the dirt while I mutter the answer under my breath. Compared to a four-stroke utility, a Banshee does need a fair amount more maintenance. But, that's like comparing apples and oranges, its just not the same.
If you compare it to say, a 250cc two-stroke racer, then the maintenance really is not any more. All two strokes need the air filter(s) cleaned and oiled on a regular basis. All two strokes require SOME jetting. That is, unless you never change your riding elevation, and you live some where with no seasons, and you really don't care about your quad's peak performance and you don't mind fouling plugs!! If you answered yes to ALL of those, disregard this next statement: you HAVE to do SOME jetting with any two stroke. Its just a fact of life with them. If this bothers you, then stick with the thumpers (four-strokes). All sport quads need the chain serviced on a regular basis, suspension pivots grease (grease zerks RULE!), and fresh tranny oil. So, what's left?? Not much.
So, if you haven't gotten the point of all that above, what I'm saying is a Banshee really doesn't take any more service than any other two-stroke performance quad out there. The only difference is you have to do some things in double (ie, jetting) This sorta leads into the next question: