The user guides from Rover are free to download from their site. Just go to the link Bushy provided for you above, look for your model number and download the pdf file. The drive belt may well have lost flex from sitting around so long unused. I have an autodrive Rancher with the 17HP version of that engine, don't bother swapping it out, it will be more than adequate for the yard you have. Probably be good idea to throw a new oil filter and an oil change at it though.
