2004-2009 Honda TRX450R/TRX450ER Service Manual, Page 234Get this manual
CYLINDERPISTON Insert the piston ring into the bottom of the cylinder squarely using the piston crownMeasure the ring end gapSERVICE LIMITS: '04'05; Top: 0.50 mm (0.020 in) Second: 0.65 mm (0.026 in) Oil (side rail): 0.9 mm (0.04 in) After '05; Top: 0.45 mm (0.018 in) Second: 0.48 mm (0.019 in) Oil (side rail): 0.90 mm (0.035 in) '04- '05: Measure the piston O.Dat point 20 mm (0.8 in) from the bottom and 90 to the piston pin holeSERVICE LIMIT: 93.86 mm (3.695 in) After '05: Measure the piston O.Dat point 10 mm (0.4 in) from the bottom and 90 to the piston pin holeSERVICE LIMIT: 95.87 mm (3.774 in) Compare this measurement against the maximum cylinder I.Dmeasurement and calculate the cylinder-to-piston clearance (page 12-7)'04-'05: 20 mm (0.8 in) After'05:10mm (0.4 in) Measure the piston pin hole I.DTake the maximum reading to determine the I.DSERVICE LIMITS: '04'05; 21.03 mm (0.828 in) After '05; 19.03 mm (0.749 in) Measure the piston pin O.Dat three pointsSERVICE LIMITS: '04'05; 20.98 mm (0.826 in) After '05; 18.98 mm (0.747 in) Calculate the piston-to-piston pin clearanceSERVICE LIMIT: 0.04 mm (0.002 in) CONNECTING ROD Measure the connecting rod small end I.DSERVICE LIMITS: '04-'05; 21.04 mm (0.828 in) After '05; 19.04 mm (0.750 in) Calculate the connecting rod-to-piston pin clearanceSERVICE LIMIT: 0.06 mm (0.002 in) PISTON RING