Is there a big preference toward a particular injection oil? Mineral or synthetic - why? One brand over another - why? My (new to me) sled has been through numerous owners and has 6600 miles on it. Runs like a top, but who knows what oils have been used in it's history. Thanks.

As the title says, new owner, new to this forum, looking for advice and what type of: Drive belt, spark plugs, engine/injection oil type, fuel type (premium, mid-grade)???? Thanks in advance for the help. Todd