On the 200's you will need a side cover gasket and a centrifugal oil filter gasket, as well as a clutch nut socket. All easily available though, Dr ATV has them, so does eBay. I bet nobody has been in there to clean it in a long long time. I have had the centrifugal oil filter come out with so much crud packed in there that you think its round inside, but its got three bumps where the bolts go through. You will see what i mean when you take it apart, it will gather a LOT of crud if nobody has done it! Get a couple cans of brake cleaner unless you got a
parts washer, clean the inside of the side cover and the centrifugal oil filter before putting it back together.
To make it a bit easier tip it on its side, lay it over on its left side, i just use a milk crate with a block of wood and some rags to prop up the front end so it lays flat on the left side rear tire. Then when you take the right cover off you won't have to deal with
parts falling out, aka the clutch lifter and lifter cam. And it makes it a lot easier to get back together. There is two clutches, the centrifugal clutch and the manual clutch. If when you put it in first and you tap the throttle it engages and you can make it hop with each throttle stab then your centrifugal clutch is working, its probably the actual clutch discs that are worn. But you have to remove the centrifugal clutch before you can get the other clutch out. The centrifugal clutch takes a 30mm socket to get the nut off, and its LEFT HAND threads, so clockwise to loosen. If you don't have an impact it can be a battle to remove, with an impact i can usually zip them off no problem, but a breaker bar and a lot of grunting will get it done! LOL