Page 548 of 698

ENGINE MECHANICAL (M13 ENGINE) 6A1-47
DISASSEMBLY
1) For ease in servicing cylinder head, remove intake manifold,
injectors and exhaust manifold from cylinder head.
2) Using special tools (Valve lifter), compress valve spring and
then remove valve cotters (1) by using special tool (Forceps).
Special tool
(A) : 09916-14510
(B) : 09916-14910
(C) : 09916-84511
3) Release special tool, and remove spring retainer and valve
spring.
4) Remove valve from combustion chamber side.
5) Remove valve stem seal (1) from valve guide, and then valve
spring seat (2).
6) Using special tool (valve guide remover), drive valve guide
out from combustion chamber side to valve spring side.
Special tool
(A) : 09916-46020 for engine equipped with 69G type valve
(A) : 09916-44910 for engine equipped with 54G type valve
7) Place disassembled parts except valve stem seal and valve
guide in order so that they can be installed in their original
position.
NOTE:
Do not reuse seal once disassembled. Be sure to use
new oil seal when assembling.
NOTE:
Do not reuse valve guide once disassembled. Be sure to
use new valve guide (Oversize) when assembling.
1. Valve
2. Emboss mark 54G or 69G
Page 549 of 698

6A1-48 ENGINE MECHANICAL (M13 ENGINE)
INSPECTION
Valve Guides
Using a micrometer and bore gauge, take diameter readings on
valve stems and guides to check stem-to-guide clearance. Be
sure to take reading at more than one place along the length of
each stem and guide.
If clearance exceeds limit, replace valve and valve guide.
Valve stem-to-guide clearance
Valve stem diameter [A]
Valve guide bore [B] standard
In and Ex : 6.000 – 6.012 mm (0.2362 – 0.2367 in.) for 69G
type valve
In and Ex : 5.485 – 5.510 mm (0.2159 – 0.2169 in.) for 54G
type valve
If bore gauge is not available, check end deflection of valve stem
with a dial gauge instead.
Move stem end in directions (1) and (2) to measure end deflec-
tion.
If deflection exceeds its limit, replace valve stem and valve guide.
Valve stem end deflection limit
In : 0.14 mm (0.005 in.)
Ex : 0.18 mm (0.007 in.)Valve type Standard Limit
69GIn0.020 – 0.047 mm
(0.0008 – 0.0019 in.)0.07 mm
(0.0028 in.)
Ex0.045 – 0.072 mm
(0.0018 – 0.0028 in.)0.09 mm
(0.0035 in.)
54GIn0.020 – 0.030 mm
(0.0008 – 0.0012 in.)0.05 mm
(0.0017 in.)
Ex0.045 – 0.055 mm
(0.0018 – 0.0022 in.)0.07 mm
(0.0028 in.)
Valve type Standard
69GIn5.965 – 5.980 mm
(0.2348 – 0.2354 in.)
Ex5.940 – 5.955 mm
(0.2339 – 0.2344 in.)
54GIn5.465 – 5.480 mm
(0.2152 – 0.2157 in.)
Ex5.440 – 5.455 mm
(0.2142 – 0.2148 in.)
1. Emboss mark 54G or 69G
Page 550 of 698

ENGINE MECHANICAL (M13 ENGINE) 6A1-49
Valves
Remove all carbon from valves.
Inspect each valve for wear, burn or distortion at its face and
stem end, as necessary, replace it.
Measure thickness “a” of valve head. If measured thickness
exceeds limit, replace valve.
Valve head thickness (In and Ex)
Standard : 1.22 – 1.55 mm (0.048 – 0.061 in.)
Limit : 0.9 mm (0.035 in.)
Inspect valve stem end face for pitting and wear. If pitting or
wear is found there, valve stem end may be resurfaced, but
not too much to grind off its chamber. When it is worn out too
much that its chamber is gone, replace valve.
Check each valve for radial runout with a dial gauge and “V”
block. To check runout, rotate valve slowly. If runout exceeds
its limit, replace valve.
Limit on valve head radial runout
: 0.08 mm (0.003 in.)
Seating contact width:
Create contact pattern on each valve in the usual manner,
i.e. by giving uniform coat of marking compound to valve
seat and by rotatingly tapping seat with valve head. Valve
lapper (tool used in valve lapping) must be used.
Pattern produced on seating face of valve must be a continu-
ous ring without any break, and the width of pattern must be
within specified range.
Standard seating width “a” revealed by contact pattern on
valve face
In and Ex : 1.1 - 1.3 mm (0.0433 - 0.0512 in.)
Page 551 of 698

6A1-50 ENGINE MECHANICAL (M13 ENGINE)
Valve seat repair:
A valve seat not producing a uniform contact with its valve or
showing width of seating contact that is out of specified
range must be repaired by regrinding or by cutting and
regrinding and finished by lapping.
a) EXHAUST VALVE SEAT : Use valve seat cutters (1) to
make two cuts as illustrated in figure. Two cutters must be
used: the first for making 15° angle, and the second for
making 45° angle. The second cut must be made to pro-
duce desired seat width.
Seat width for exhaust valve seat
“a” : 1.1 – 1.3 mm (0.0433 – 0.0512 in.)
b) INTAKE VALVE SEAT : Use valve seat cutters to make
three cuts as illustrated in figure. Three cutters must be
used: the 1st for making 15° angle, the 2nd for making 60°
angle, and 3rd for making 45° angle. The 3rd cut (45°) must
be made to produce desired seat width.
Seat width for intake valve seat
“b” : 1.1 – 1.3 mm (0.0433 – 0.0512 in.)
c) VALVE LAPPING : Lap valve on seat in two steps, first with
coarse size lapping compound applied to face and the sec-
ond with fine-size compound, each time using valve lapper
according to usual lapping method.
Cylinder Head
Remove all carbon deposits from combustion chambers.
NOTE:
Do not use any sharp-edged tool to scrape off carbon
deposits. Be careful not to scuff or nick metal surfaces
when decarbonizing. The same applies to valves and
valve seats, too.
Page 552 of 698

ENGINE MECHANICAL (M13 ENGINE) 6A1-51
Check cylinder head for cracks on intake and exhaust ports,
combustion chambers, and head surface.
Using a straightedge and thickness gauge, check flatness of
gasketed surface at a total of 2 locations. If distortion limit,
given below, is exceeded, correct gasketed surface with a
surface plate and abrasive paper of about #400 (Waterproof
silicon carbide abrasive paper): place abrasive paper on and
over surface plate, and rub gasketed surface against paper
to grind off high spots. Should this fail to reduce thickness
gauge readings to within limit, replace cylinder head.
Leakage of combustion gases from this gasketed joint is
often due to warped gasketed surface: such leakage results
in reduced power output.
Limit of distortion for cylinder head surface on piston side
: 0.03 mm (0.001 in.)
Distortion of manifold seating faces:
Check seating faces of cylinder head for manifolds, using a
straightedge and thickness gauge, in order to determine
whether these faces should be corrected or cylinder head
replaced.
Limit of distortion for cylinder head surface on intake and
exhaust manifold
: 0.05 mm (0.002 in.)
Page 553 of 698

6A1-52 ENGINE MECHANICAL (M13 ENGINE)
Valve Springs
Referring to data given below, check to be sure that each
spring is in sound condition, free of any evidence of break-
age or weakening. Remember, weakened valve springs can
cause chatter, not to mention possibility of reducing power
output due to gas leakage caused by decreased seating
pressure.
Valve spring free length for engine equipped with 69G
type valve
Standard : 43.00 mm (1.693 in.)
Limit : 42.00 mm (1.652 in.)
Valve spring free length for engine equipped with 54G
type valve
Standard : 36.83 mm (1.450 in.)
Limit : 35.83 mm (1.410 in.)
Valve spring preload for engine equipped with 69G type
valve
Standard : 110 – 126 N (11.2 – 12.8 kg) for 39.50 mm
(24.7 – 28.2 lb/1.555 in.)
Limit : 105 N (10.7 kg) for 39.5 mm (23.6 lb/1.555 in.)
Valve spring preload for engine equipped with 54G type
valve
Standard : 107 – 125 N (10.7 – 12.5 kg) for 31.50 mm
(23.6 – 27.6 lb/1.240 in.)
Limit : 102 N (10.4 kg) for 31.50 mm (22.9 lb/1.240 in.)
Spring skewness:
Use a square and surface plate to check each spring for
skewness in terms of clearance between end of valve spring
and square. Valve springs found to exhibit a larger clearance
than limit given below must be replaced.
Valve spring skewness
Limit : 2.0 mm (0.079 in.) for engine equipped with 69G
type valve
Limit : 1.6 mm (0.063 in.) for engine equipped with 54G
type valve
1. Valve
2. Emboss mark 54G or 69G
1. Valve
2. Emboss mark 54G or 69G
Page 554 of 698

ENGINE MECHANICAL (M13 ENGINE) 6A1-53
ASSEMBLY
1) Before installing valve guide into cylinder head, ream guide
hole with special tool (11 mm reamer for engine equipped
with 69G type valve or 10.5 mm reamer for engine equipped
with 54G type valve) so as to remove burrs and make it truly
round.
Special tool
(A) : 09916-34542
(B) : 09916-38210 (11 mm) for engine equipped with 69G
type valve
(B) : 09916-37320 (10.5 mm) for engine equipped with 54G
type valve
2) Install valve guide to cylinder head.
Heat cylinder head uniformly to a temperature of 80 to 100
°C (176 to 212 °F) so that head will not be distorted, and
drive new valve guide into hole with special tools. Drive in
new valve guide until special tool (Valve guide installer) con-
tacts cylinder head.
After installing, make sure that valve guide protrudes by
specified dimension “a” from cylinder head.
Special tool
(A) : 09916-57350 (For engine equipped with 69G type
valve)
(A) : 09916-58210 (For engine equipped with 54G type
valve)
(B) : 09917-88240 (For Intake side of engine equipped with
69G type valve)
(B) : 09917-88250 (For Exhaust side of engine equipped
with 69G type valve)
(B) : 09916-56011 (For both sides of engine equipped with
54G type valve)
Specification for valve guide protrusion “a”
Intake side of engine equipped with 69G type valve
: 17.5 mm (0.71 in.)
Exhaust side of engine equipped with 69G type valve
: 14.5 mm (0.57 in.)
Both sides of engine equipped with 54G type valve
: 11.1 – 11.5 mm (0.44 – 0.45 in.)
1. Valve
2. Emboss mark 54G or 69G
NOTE:
Never reuse once-disassembled valve guide.
Make sure to install new valve guide.
Intake and exhaust valve guides are identical.
1. Valve
2. Emboss mark 54G or 69G
Page 555 of 698

6A1-54 ENGINE MECHANICAL (M13 ENGINE)
3) Ream valve guide bore with special tool (6.0 mm reamer for
engine equipped with 69G type valve or 5.5 mm reamer for
engine equipped with 54G type valve). After reaming, clean
bore.
Special tool
(A) : 09916-34542
(B) : 09916-37810 (6 mm) for engine equipped with 69G
type valve
(B) : 09916-34550 (5.5 mm) for engine equipped with 54G
type valve
4) Install valve spring seat to cylinder head.
5) Install new valve stem seal (1) to valve guide.
After applying engine oil to seal and spindle of special tool
(Valve guide installer handle), fit oil seal to spindle, and then
install seal to valve guide by pushing special tool by hand.
After installing, check to be sure that seal is properly fixed to
valve guide.
Special tool
(A) : 09917-98221
(B) : 09916-57350 (For engine equipped with 69G type
valve)
(B) : 09916-58210 (For engine equipped with 54G type
valve)
6) Install valve to valve guide.
Before installing valve to valve guide, apply engine oil to
stem seal, valve guide bore and valve stem.
1. Valve
2. Emboss mark 54G or 69G
NOTE:
Do not reuse once-disassembled seal. Be sure to
install new seal.
When installing, never tap or hit special tool with a
hammer or else. Install seal to guide only by pushing
special tool by hand. Tapping or hitting special tool
may cause damage to seal.
2. Valve
3. Emboss mark 54G or 69G