2003-2006 Kawasaki KFX400 service manual, Page 108Get this manual
PISTON AND PISTON RING
PISTON DIAMETER Measure the piston diameter using the micrometer at 15 mm (0.6 in) from the skirt endIf the piston diameter is less than the service limit, replace the piston with new one09900-20204: Micrometer (75 100 mm) Piston diameter Service Limit: 89.880 mm (3.5386 in) PISTON-RING-TO-GROOVE CLEARANCE Measure the side clearances of the 1st and 2nd piston rings using the thickness gaugeIf any clearance reading exceeds the service limit, replace both the piston and piston rings09900-20803: Thickness gauge 09900-20205: Micrometer (0 25 mm) Piston-ring-to-groove clearance Service Limit: 1st: 0.180 mm (0.007 in) 2nd: 0.150 mm (0.006 in) Piston ring groove width Standard: 1st: 0.78 0.80 mm (0.0307 1.30 1.32 mm (0.0512 2nd: 0.81 0.83 mm (0.0319 Oil: 2.01 2.03 mm (0.0791