What year Griz? I don’t know that I would go through all that trouble. If it’s running well then go enjoy it. A complete service including all fluids and a check of all wear items is always a good idea on a used machine.
I get it. You would like to have the bike in pretty much "new" condition. This is what I would suggest, if it runs and handles well now.I bought my Grizzly used back in December with 1200 miles and 500 hours, I have put some work in it to get it running and riding well and enjoyed it some during the snow. I’m considering the idea of tearing the bike completely down and inspecting every part/replace what’s worn and repaint everything that has rust or needs a touching up. Change all the fluids while it’s apart as I have no idea when they were last done. I have some mechanical experience but never taking anything apart as complex as this seems. How much would I need to remove from the engine to pull it? And what’s a good way to make sure everything goes back together the right way?