Regarding changing shafts. Make sure you really need to , double check where the seal actually rides. I bought a used sled that someone drove the seal beyond where it needed to be. Drove seals to proper position with no problem. Repair manual is very helpful.
Thanks for all the help. Joined forum after getting burned buying a 2001 zrt 800. Found some good advise . Bought a sled with 1 new cylinder and piston but the cause was never fixed. Rode 80 miles and it took out the pto piston again with the center one not far behind. Ended up with bad carbs...