I had 2 MDS's , and both died of the same thing. Broken conrods. With both engines, the little end wasn't bushed and they chewed up pretty quick. If I had 2 conrods, I would still have both of those engines running because the rest of them is like new, both inside and out. Both of mine were 40's and made power well beyond their requirement and throttled brillantly with their standard carb but the conrod couldn't hack it.