The JE single piston for 1999–2008 Honda TRX 400EX is listed at an 85mm bore with a 10.5:1 compression ratio and supplied individually for targeted service. Meant for rebuilds or repairs on that range of TRX models, it matches the stated bore and compression requirements. Use this single piston when one cylinder needs replacement during maintenance or overhaul.
JE Pistons 99-08 Honda TRX 400EX - 85MM/10.5 to 1 Piston Single