Re: Greetings from Colorado
Flex conduit doesn't work. It leaks, badly. The wraps are not gas/oil/exhaust tight. Some guys have had luck with the flexible gas lines used for appliance hook-up to a gas supply. It is bendable and holds pressure, comes in copper or stainless steel. You'll have to devise some fittings for the ends but it can be done. Good luck, keep us posted.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"