Honda SH300I 2006, Manual

Page: 219 / 511

CYLINDER HEAD/VALVES
9-3
SERVICE INFORMATION
GENERAL
• This section covers service of the rocker arms, camshaft, valves and cylinder head. These parts can be serviced with the
engine installed in the frame.
• When disassembling, mark and store the disassembled parts to ensure that they are reinstalled in their original loca-
tions.
• Clean all disassembled parts with cleaning solvent and dry them by blowing them off with compressed air before
inspection.
• The rocker arm and camshaft lubricating oil is fed through the oil passages in the cylinder head and head cover. Clean
the oil passages before assembling.
• Be careful not to damage the mating surfaces when removing the cylinder head cover and cylinder head.
SPECIFICATIONS
Unit: mm (in)
TORQUE VALUES
ITEM STANDARD SERVICE LIMIT
Cylinder compression at 450 min
-1
(rpm) 1,569 kPa (16.0 kgf/cm
2
, 228 psi) –
Camshaft Cam lobe height IN 39.325 – 39.485 (1.5482 – 1.5545) 39.295 (1.5470)
EX 37.034 – 37.194 (1.4580– 1.4643) 37.034 (1.4580)
Cylinder head warpage – 0.05 (0.002)
Rocker arm Arm I.D. IN/EX 13.000 – 13.018 (0.5118 – 0.5125) 13.10 (0.516)
Shaft O.D. IN/EX 12.966 – 12.984 (0.5105 – 0.5112) 12.91 (0.508)
Arm-to-shaft clear-
ance
IN/EX 0.016 – 0.052 (0.0006 – 0.0020) 0.08 (0.003)
Side spring free length 17.1 (0.67) 15.5(0.61)
Valve,
valve guide Valve clearance IN 0.16
±
0.03 (0.006
±
0.001) –
EX 0.22
±
0.03 (0.009
±
0.001) –
Valve stem O.D. IN 4.475 – 4.490 (0.1762 – 0.1768) 4.465 (0.1758)
EX 4.465 – 4.480 (0.1758 – 0.1764) 4.455 (0.1754)
Valve guide I.D. IN/EX 4.500 – 4.512 (0.1772 – 0.1776) 4.54 (0.179)
Stem-to-guide clear-
ance IN 0.010 – 0.037 (0.0004 – 0.0015) 0.08 (0.003)
EX 0.020 – 0.047 (0.0008 – 0.0019) 0.09 (0.004)
Valve guide projection
above cylinder head
IN 11.20 – 11.50 (0.441 – 0.453) –
EX 12.20 – 12.50 (0.480 – 0.492) –
Valve seat width IN/EX 0.90 – 1.10 (0.035 – 0.043) 1.5 (0.06)
Valve spring free length IN/EX 37.09 (1.460) 35.6 (1.40)
Cylinder head bolt 38 N·m (3.9 kgf·m, 28 lbf·ft) Apply engine oil to the threads and seating
surface.
Cam stopper plate bolt 12 N·m (1.2 kgf·m, 9 lbf·ft) Apply locking agent to the threads.
Cam sprocket bolt 16 N·m (1.6 kgf·m, 12 lbf·ft) Apply locking agent to the threads.
Cam chain tensioner lifter sealing bolt 22 N·m (2.2 kgf·m, 16 lbf·ft)
Timing hole cap 6 N·m (0.6 kgf·m, 4.4 lbf·ft) Apply engine oil to the threads and seating
surface.
Cylinder head cover bolt 10 N·m (1.0 kgf·m, 7 lbf·ft)