People seem to forget we have manufacture support right here on RCU. If you go into the gas engine forum then go into the sub forum, glow engines you will find factory reps for most major brands of engines. For OS we have Bill Baxter. Bill knows the OS line of engines forwards and backwards. I'm sure Bill can give you and anyone on the net all the facts you need and probably bring up the photos to clear things up for you. Nice guy, has helped me out a few times when I have had questions. Give it a try.