Here's something to think about, I have a "LAWN BOY" two cycle engine under the bench that I have been saving in case the one I use for mowing the lawn dies. I have only had the one I use 12 years, and I was the second owner. So, I have looked at a conversion. I know it will need a pumper carb, but it has a double reed valve, two rings, and good compression. Haven"t figured the displacement yet, and temp has been below "0" the past couple nights. Will send more info when I get it. Flathead 4