Originally Posted by johnhi

Well look what happend to my engine on Friday. I had two good flights, and then started the engine for the 3rd flight and within 20 seconds of runng it suddenly started to make a knocking sound. I shut down immediately and noticed that number 2 cylinder had cracked at the base. As you know from my run in period earlier in this forum blog the engine whas VERY cearfully run-in and I have subsequently had about 25 flights with no issues. Hopfully it will just need a replacement cylider and piston ring.