Domshook

I recently got a 2003 yamaha kodiak 450 with a bad starter clutch. And when i go to replace it i noticw there is no woodruff key and the brass bushing was split. Now i have to basically press on my idler gear. Im pretty sure this is wrong and i need help i have tried 2 different companys. Please help. There is no play in the crankshaft and no obivous marks or wear signs.