i have a 2002 honda rancher es with 1900 miles and 280 hours on it. it smokes when i rev it or drive it. it starts up fine and does not tick knock or anything. it runs fine it just smokes when riding/revving. it has plenty of power and everything. i also noticed a little oil in the bottom of the tank that the air filter is located. what is the possible problem and solution? also, when i purchased the wheeler, the guy told me it had sat around without being started for a year.