2-RING A Piston KIT 92.00 mm Bore STD Compresion 12.5:1

Ready to install, ProX Piston Kits are supplied complete with piston rings, wrist pin, and circlips. - ProX pistons are precision machined on the latest, state of the art CNC equipment and use the same low-expansion, low-friction piston alloy all major Japanese engine manufacturers use. - Uses an OEM style tin coating to assist the break-in process when you first start your machine.

Replacements parts. PROX RING SET 02.2419

Yamaha WR400F (1998-2000),
Yamaha YZ400F (1998-1999),

PROX 01.2419.B