Honda TRX70 Fourtrax 1986 User Manual

SERVICE INFORMA nON
TROUBLESHOOTING
CYLINOER HEAO REMOVAL
CYLINDER
HEAD DISASSEMBLY
SERVICE INFORMATION
GENERAL
6. CYLINDER HEAD/VALVES
6-1
6-2
6 -3
6-4
VALVE GUIDE REPLACEMENT
VALVE SEAT INSPEcnON /REFACING
CYLINDER
HEAD ASSEMBLY
CYLINDER HEAD INSTALLATION
6-7
6-8
6-10
6- 12
• This section covers maintenance and inspection of the cylinder head, valves, camshaft and rocker arms. These services r:
can be done with the engine installed. -=
• Camshaft and rocker arm lubricating oil is fed through oil passages. Be sure the passages are not clogged.
• During assembly, apply molybdenum disulfide greese 10 the cam shaft journal to provide initial lubrication .
• Be sure to use a new gasket and D·rings w"'en installing the cylinder head.
SPEC IFI CAT IONS
mm lin )
ITEM
STANDARD
SERVICE LIMIT
Compression pressure
1 . 200~ 150kPa 900 kPa
1l2 .0 :!: 1.5kg / cm
2
. 170 :!:21 psi I
19.0 kg/cm
1
,
128 psi!
Camshaft Cam lobe
'N .
26 . 0711.026) 25.69 (1.0 11 )
height
EX.
26 . 07 11 .026) 25.69 11.011)
Oil clearance
0. 010 - 0. 025 (0. 0004 - 0. 0010) 0.05 (0. 002)
Rocker arm shaft 0 .0 .
9. 978 - 9. 989 (0. 3928 - 0. 3933) 9. 91 10 . 390)
Rocker arm 1.0. 10 . 000 - 10 . 015 ( 0.3937 - 0. 3943 )
10 . 10 (0. 398)
Valve spring Free len ij th Inner
25 .1 (0. 99 ) 23 .9 (0. 94 )
Outer
28 . 111.111
26 .9 (1 . 06)
Preload/l ength Inner 2. 45 - 2. 75 kg/ 22 .7 2.3 kg/ 22 .7
( 5.401 - 6. 063 Ibs/0 . 89)
(5. 07 Ibs/0 . 89)
Outer 6. 65 - 7. 75 kg/ 24.9 6.3 kg/ 24 .9
(14. 661 - 17.086Ibs /O.98\ 113. 89 Ib s/0. 98)
Valve guidel Val ve s tem
'N .
5.455 - 5.465 (0.2148 - 0.2152 1
5.40 10 . 213)
valve
0 .0 .
EX .
5. 435 - 5.445 (0. 2140 - 0. 2144 1
5.40 (0. 213)
V al ve guide
'N.
5.475 - 5. 485 (0. 2156 - 0. 2159) 5.50 10 . 217)
1.0 .
EX .
5. 475 - 5. 485 (0 . 2156 - 0. 2159 1 5.50 10 . 217)
Stem · to - gu ide
'N.
0. 010 - 0. 03010 . 0004 - 0. 0012 )
0. 08 (0. 003)
ctearan ce
EX. 0. 030-0 . 050 (0.0012 - 0.0020 )
0.10 (0. 004)
Valve seat wi dth
1. 010 . 04)
1.6 (0. 06)
Cylinder head warpage
-- 0.05 10 .0021
6-1

Honda TRX70 Fourtrax 1986 Specifications

General

Brand	Honda
Model	TRX70 Fourtrax 1986
Category	Offroad Vehicle
Language	English