I had one of those. The very first AAC Sirio .12. That thing when cold could be spun over like a pan car axle with no motor. I swear it had no compression at all. Despite this, the damn thing would still start. It would run kind of rich for a few laps but once it warmed up (never more than just a few laps) it would outright scream. Won a few nice races with that motor. I then sold it to someone who sold it to someone, etc. etc. Now a buddy of mine has it and still runs it in the occasional dirt oval race.