Suzuki RM-Z450 - Piston Ring Groove Width; Piston Ring Thickness; Piston Ring End Gap

6-21 CYLINDER HEAD, CYLINDER AND PISTON
PISTON RING-TO-GROOVE CLEARANCE
• Decarbonize the piston ring and piston ring groove.
• Measure the side clearances of the 1st piston ring using the
thickness gauge.
• If any of the clearances exceed the limit, replace both the pis-
ton and piston ring.
# 09900-20803: Thickness gauge
09900-20205: Micrometer (0 – 25 mm)
" Piston ring-to-groove clearance:
Service Limit (1st): 0.180 mm (0.007 in)
" Piston ring groove width:
Standard (1st) : 0.78 – 0.80 mm (0.0307 – 0.0315 in)
: 1.30 – 1.32 mm (0.0512 – 0.0520 in)
(Oil) : 2.01 – 2.03 mm (0.0791 – 0.0799 in)
" Piston ring thickness:
Standard (1st) : 0.71 – 0.76 mm (0.0279 – 0.0299 in)
: 1.08 – 1.10 mm (0.0425 – 0.0433 in)
PISTON RING FREE END GAP AND PISTON RING END GAP
• Measure the piston ring free end gap using the vernier cali-
pers.
• Next, fit the piston ring squarely into the cylinder and measure
the piston ring end gap using the thickness gauge.
• If any of the measurements exceed the service limit, replace
the piston ring with a new one.
" Piston ring free end gap:
Service Limit (1st): 6.9 mm (0.27 in)
# 09900-20101: Vernier calipers
" Piston ring end gap:
Service Limit (1st): 0.50 mm (0.020 in)
# 09900-20803: Thickness gauge