Anybody know 4 stroke quads???

Well I just picked up two quads for enjoyment, still got my bike tho, but havent been on a quad in over 7yrs at least and never messed with a 4 stroke before. Always had racing quads. I dont plan on jumping this thing or anything of the sort but need to know how to change the oil and filter and where i can find it on a 97 and 98 Yamaha warrior. I know some of you have quads also so i thought i'd ask. I dont have a manual yet but should in a week or so but I wanted to get that out of the way quick. Also how does one go about adjusting valves, I dont want to take these to a shop or anything, it has a tendency to sputty and stall if I give it to much gas from idle, think it may be a top end? just thought I would throw a few things out there. Hope someone can help... Thanx

That sounds like gibberish to me, but I do have the carb apart and i'll tell you what, there are more screws on the carb then there is on my whole bike. Going to inspect everything as see what happens. Any other ideas??