Kipor KG390, Service Manual

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5
2.6 Maintenance standards
Part Item Standard in. (mm
）
Service limit
Maximum speed without load 3780rpm
Engine
Compression 0.55MPa/600rpm
Cylinder block Sleeve I.D 88.015~88.035 88.17
Skirt O.D 87.96~87.98 87.85
Piston
Pin bore I.D 20.002~20.008 20.05
Piston pin O.D 19.994~20.000 19.95
Height 1.97~1.99 1.87
side clearance 0.02~0.06 0.15
end clearance 0.2~0.35 1.0
1
st
ring/2
nd
ring
Thickness 3.9~4.1 3.7
Height 2.68~2.75 2.58
side clearance 0.055~0.14 0.20
end clearance 0.20~0.50 1.0
Piston ring
Oil ring
Thicknesss 2.9~3.3 2.8
Small end I.D 20.007~20.020 20.09
Connecting rod
Large end I.D 36.015~36.025 36.09
Crankshaft Main Journal O.D 35.960~35.975 35.90
IN 0.10±0.02
Valve clearance
EX 0.15±0.02
IN 6.570~6.585 6.50
Stem O.D
EX 6.550~6.570 6.50
Guide I.D IN / EX 6.600~6.622 6.68
Valves and
valve guide
pipe
Seat width IN / EX 0.8~1.2 2.0
Valve spring Free length IN / EX 39 37.5
IN 32.60~32.80 32.25
Cam wheel Cam height
EX 32.09~32.29 31.75
Camshaft O.D 15.980~15.990 15.920
Valve lifter O.D 8.96~8.98 8.87
Cylinder block
Valve lifter I.D
Camshaft bearing I.D
9.000~9.015
16.000~16.018
9.06
16.05
Crankcase back
cover
Camshaft bearing I.D 16.000~16.018 16.05
Spark plug
Air gap
0.7~0.8
Primary side 0.8~1.3 Ω
Ignition coil Resistance
Second side 15~21K Ω
Pulse coil
（
trigger head
）
Air gap
Resistance
0.5~0.75
80~130 Ω
Electromagnetic
valve of
carburetor
Resistance 6 ～ 8 Ω