Suzuki RA410 Manual page 335

6A4-76 ENGINE MECHANICAL
Cylinder Block
Distortion of gasketed surface
Using straightedge and thickness gauge, check gasketed surface
for distortion and, if flatness exceeds its limit, correct it.
Limit of distortion : 0.05 mm (0.020 in.)
Honing or reboring cylinders
1) When any cylinder needs reboring, all other cylinders must also
be rebored at the same time.
2) Select oversized piston according to amount of cylinder wear.
3) Using micrometer, measure piston diameter.
1. 19 mm (0.75 in.)
4) Calculate cylinder bore diameter to be rebored.
D = A + B – C
D: Cylinder bore diameter to be rebored.
A: Piston diameter as measured.
B: Piston clearance = 0.02 – 0.04 mm
C: Allowance for honing = 0.02 mm (0.0008 in.)
5) Rebore and hone cylinder to calculated dimension.
NOTE:
Before reboring, install lower crankcase and tighten to
specification to avoid distortion of bearing bores.
6) Measure piston clearance after honing.
Size
O/S 0.25
O/S 0.50
(0.0008 – 0.0015 in.)
Piston diameter
68.220 – 68.240 mm
(2.6858 – 2.6866 in.)
68.470 – 68.490 mm
(2.6957 – 2.6965 in.)