I believe I am having some trouble with my sled, i have been riding it in the yard and I have out about 25 miles on it this year. It has used about a 1/4 tank of gas. Last year, i know i was having trouble because on a snow day I had riden about two miles and used a 1/4 tank. I guess my question is, what could have been my problem, and how can I fix this?