Eton America Beamer PN2 Service Manual page 26

Insert each piston ring into the cylinder, and
measure the end gap.
Service limit: 0.5 mm
Measure the clearance between the ring and
groove.
Service limit: 0.09 mm
Measure the pistons outer diameter at 10 mm
above the bottom.
Service limit: 39.9 mm
Beamer Rev-2.0.2 Page 26 of 55 11/21/2005