Well I decided to go with the Ryobu 31cc engine. How will I know when I go to Walmart if it is the newer twin ring piston version? Will this engine work on a Stinger 1.20? What kind of performance can I get out of this combo? Would you guys happen to have any step by step pictures of the entire conversion process? I am very new at this conversion stuff and would hate to screw up a perfectly good engine. I would really love to see some pictures. Thanks in advance!!!