Cylinder Head/Valves Service Information; Cylinder Head/Valves Torque Values - Honda 2010 CRF250R Service Manual

SERVICE INFORMATION
GENERAL
CYLINDER HEADNALVES
This section covers service of the camshaft. cylinder head , valves and cam chain tensioner. These services can be done wi th
the engine Installed in the frame.
During disassembly , mark and store the disassembled parts to ensure that they are reinstalled in their original locations.
Clean all disassembled parts wi th cleaning solvent and
dry
them by blowing them off with compressed air before inspectIOn.
Camshaft lubrication oil is fed through oil passages
In
Ihe cylinder head and camshaft holders. Clean the oil passages before
assembling them.
Be careful nollo damage the mating surfaces when removing the cylinder head cover and cylinder head.
SPECIFICATIONS
Cylinder compression
Cylinder head warpage
ITEM
STANDA RD
598"'kp
O
a " "(SCC . 1"kgflcm
l ,
87 pSI)
at
cranking
Un!! : mrn (in )
SERVICE LI MIT
Valve and valve I Valve clearance- - --
guide
IN
EX
IN
EX
_ __ _ 0.05 (0.0021
0.12 ± 0.03 (0.005 ± 0.001) _ __ _
~
0.28 ± 0.03 (0.011 ± 0.001)
Valve stem 0 .0 .
Valve guide 1.0.
IN
4.455 (0.1754)
----i 5:,:. 0~ 52
(0 19891
_ _
~ 4 .~ 55 = 2
(0 .17921
Slem-to..guide clearance
EX
IN
EX
IN
EX
IN/EX
IN
EX
4.975 4.990 (0.1959 - 0.1965)
4.465 - 4.480 (0.1758 - 0.1764)
5.000 - 5.012 (0.1969 - 0.1973)
4.500 - 4.512 (0. 1772 - 0.1776)
0.010 0.037 (0.0004 - 0.0015)
0.020 0.047 (0.0008 - 0.0019)
Valve guide projection
above cylinder head
Valve seat wid""" h - - - - --
15.4 - 15.6 (0.606 0.614 )
21 .3 - 21.5 (0.839 - 0.847)
0.90 1. 10 (0.035 0 .043) n .7 (0.07)
42.50 (1.673) . 42.1 p .66)
46.71 (1.839) 46.3 (1 .82)
Valve spring free length
Rocker arm Rocker arm 1.0.
Rocker
arm~ S~ha~ft~Og;' .D~.;:~~
Rocker arm·lo-shafl clearance
Cam lobe height
13.000 - 13.018 (0.511 8 - 0.5125) - 13.025 (0.5128 )
12.977 12.985 (0.5109 - 0.5112) 12.97(0.511 )
0.015 - 0.041 (0.0006 - 0.0016) 0.055 (0.0022)
Camshaft
Valve lifter 0.0.
Valve lifter bore 1.0 .
TORQUE VALUES
Breather plate bolt
Cylinder head
cover
bolt
Camshaft holder mounting bolt
Cylinder head bolt
Cam chain tensioner bolt
Crankshaft hole cap
Cylinder head hanger bolt
Cylinder head hanger plate bolt
Shock absorber upper mounting nul
Insulator band screw
(Cylinder head side)
IN
EX
36 200 - 36.440 {1.4252 - 1.434:"6 "1- - 36.06 (1 420)
25524 - 25.764 (1 .0049 - 1.0143) 25.41 (1 000)
22.478 - 22.493 (0 .8850 -
o
8855t 22 .47 (0 .885)
22 .510 - 22.526 (0 .8862 - 0.8868
cc l _ _
c..-' 2 ", 2". 54 c (O.887)
12 N·m (1.2 kg f m, 9 Ibf-ft)
10 N·m (1.0 kgf-m , 7Ibf-ft)
16 N·m (1 _ 6 kgf m, 12 IbHI)
45 N'm (4.6 kgf
m.
33 IbHt)
12 N·m (1.2 kgf m, 9 Ibf·ft)
15 N·m (1.5 kgfm, 11 IbHt)
54 N·m (5.5 kgf-m, 40 Ibf-ft)
33 N·m (3.4 kgf·m, 24 Ibf-ft)
44 N·m (4 .5 kgf·m, 32 Ibf-ft)
See page 8-29
Apply locking agent 1 0 the threads (page 8-8).
Apply engine oil 10 the threads.
Apply engine oil 10 the threads and seating
surface
Apply locking agent 10 the threads (page 8-37).
Apply grease to the threads.
U-nul
8-3