I have a 04 Kodiak 450 that won't go over 15mph. studders and back fires when given full throttle. Smokes like a freight train. It's burning oil for sure. I put a new spark plug and it ran awesome for 5 mins even got up to 48mph, was still smoking tho. Then all of a sudden it feel off and I was back to 15mph. So I think I need to rebuild the top in. New piston12:1, rings, some hot cams, top end seals. Also a carb rebuild and a fuel system flush. My question is will I need to remove then engine to do this? What do I need to take off? What other parts should I replace? What will need to be removed to do the job? Also where is the best place to get these parts?