7. CYLINDER HEAD/VALVES
7-2
PEOPLE S 4T
SERVICE INFORMATION
GENERAL INSTRUCTIONS
• The cylinder head can be serviced with the engine installed in the frame.
• When assembling, apply molybdenum disulfide grease or engine oil to the valve guide movable
parts, valve arm and camshaft sliding surface for initial lubrication.
• The camshaft is lubricated by engine oil through the cylinder head engine oil passages. Clean the
oil passages before assembling the cylinder head.
• After disassembly, clean the removed parts and dry them with compressed air before inspection.
• After removal, mark and arrange the removed parts in order. When assembling, install them in
the reverse order of removal.
SPECIFICATIONS
Standard (mm) Service Limit (mm)
Item
50 cc 50 cc
IN 0.10
-
Valve clearance (cold)
EX 0.10
-
Cylinder head compression pressure
18 (kg/cm²)
-
Cylinder head warpage
--
IN 25.7611 25.3
Camshaft cam height
EX 25.5628 25.2
IN 10.000-10.015 10.10
Valve rocker arm I.D.
EX 10.00-10.015 10.10
IN 9.972-9.987 9.91
Valve rocker arm shaft
O.D.
EX 9.972-9.987 9.91
IN 1.0 1.8
Valve seat width
EX 1.0 1.8
IN 4.4975-4.499 4.40
Valve stem O.D.
EX 4.455-4.470 4.40
IN 4.500-4.512 4.580
Valve guide I.D.
EX 4.500-4.512 4.580
IN 0.010-0.037 0.08
Valve stem-to-guide
clearance
EX 0.030-0.057 0.10