G13BB Engine. This was originally from a 1999 Geo Metro. It was used in a Ultralight aircraft for many years. Eventually the compression in a couple cylinders was getting low so I was going to rebuild it. At that time during covid the rebuild shops were telling me 6 to 12 months. They recommended I purchase a used motor and leave that to be rebuilt since the aircraft was still flying fine. Thats what I did and eventually replaced this engine. I expect the newly rebuilt motor to last many years so I really don't need this engine laying around. This engine was running fine when replaced, just low compression in cylinders 3 and 4.