Help Identifying a 100 cc ATK reed kart engine

[Terry Bentley]

Just about any of the Italian engine pistons will fit that engine using a 50mm bore. The PCR-100, ATK-100, PC-93. I think even the PRD 100 piston port engines use an interchangeable piston. Some of the later IAME engines have the same piston too. That should include the Sirio, Komet, and Parilla.

The ATK-100 showed up at Daytona in 1989 and dominated the stock classes until it was superseded but the newer model the PC-93 a few years later.