All they are is a SA-200 with a Yanmar 4TNE88 engine in it. My brother took his in and had it converted two years ago and loves it. It only uses about 3-4 gallons a day. They took it completely apart and went through every thing and maid it like brand new. He went to American Welding Supply in Groves, Texas and I think the bill was around 6K but don't quote me.