Hi Spud,
Genuine pistons were made by ELKO (Austrian firm). Today, no OEM are interested to rebuild such forged pistons.
The SWM Rotax engine fit a 18 mm piston crank in various diameter from 54 to 78 mm (depending on capacity).
Visit the site www.rotaxsales.be in Belgium (French written) for searching 76 mm pistons.
I own a NOS 54,20 mm piston for a TL125.
Hope this helps.
Cdt,
Claudio
