Update. I received an e-mail from my friend who use to be stationed with me. He just got back from Balad AB in Iraq, and he tells me the Homelite engine he sold me was a 25cc weed eater motor. He says he doesn’t convert weed eaters anymore, and that he uses chainsaw motors now. They get more horsepower, and don't require any trimming of metal except cutting off the shaft on the chain side. So now that I know its a 25cc weed eater, is the 18 x 8 prop to big for this engine?