15
3.Swirl the when spark plug and tighten to 18～20N.m by box
key ,then fix the spark plug cap when assembling.
2.3 Inspection of cylinder, piston and piston ring
Camshaft lube is injected by a hole of engine body into
cylinder, so the hole must not jam. It is necessary to fix
the cushion and adjust without dust permeated into the crank
case before assembly.
item
standard value:mm
limit value:mm
cylinder
bore diameter of cylinder
φ
102
～φ
102.03
φ
102.1
taper
0.0040
0.005
out of roundness
0.0035
0.005
degree of touristy
0.04
0.06
Piston,
piston ring
and piston
pin
external diameter of piston
φ101.95～φ101.97
φ101.92
bore diameter of piston pin
hole
φ22.002～φ22.010
φ22.010
gap between piston pin and
piston pin hole
0.007
～
0.020
0.02
Piston ring
end
clearance
Top ring/the
second ring
0.25
～
0.40
0.5
gap between
piston ring
and piston
groove
oil ring
0.3
～
0.9
1.2
top ring
0.3
～
0.07
0.10
the second
ring
0.02
～
0.06
0.09
gap between cylinder and
piston
0.03
～
0.08
0.09
external diameter of piston
pin
φ21.995～φ21.990
φ21.96
connecting
rod
bore diameter
φ22.016～φ22.027
φ22.03
Gap between small end of
connecting rod and piston
pin
0.016～0.033
0.035
