Thanks a lot for the help w8ye and foodstick. A couple of days ago I was reading that exact thread but probably made it to about page 15. There is a lot of helpful info there and I will continue that "book" to find info for gasoline. I was concerned with the 31 cc being too long. Im thinking that a poulan 25 cc with CH ignition will be the best option. I have heard this engine weighs in at 40 oz. with that ignition.