Since there is interest in the Leckich Company engines here I'll pass this along. Before the 480cc Pilot came out Mr. Leckich was working on a new
Engine that had after market cases (not his design) and used a 1981 KTM 495 piston port cylinder and head. It used a Comet snowmobile clutch. He used the Comet clutch on all of his "house" engines. He had a custom crank made for it and got it running for tests but before he could redesign a lighter crank for production the 480 Pilot came out. The sanctioning body put a 490 CC limit on the class and he never finished it. During testing this Engine was a beast. He used the clutch setup for the 360 Engine and found it would lift the front wheels a foot off the ground from a standing start in the alley by the shop.
Other builders were using Kawasaki 500 top ends and the sanctioning body wanted to stop any Engine war before it started.