IS there a right and wrong way to install the piston on a ryobi trimmer model RY30002A

Ed, June 2010

There is always a right and wrong, the piston has a ring peg to stop the ring rotating in the groove, get it wrong and it will destroy the cylinder, most machines will have an arrow on top of the piston which will normally face toward the exhaust with the ring gap at the inlet side

Husqvarna man, June 2010