Suzuki 2000 Grand Vitara SQ416, Service Manual

Page: 385 / 729

YH4
GRAND
VITARA
ENGINE MECHANICAL (H25 ENGINE) 6A2-61
1. Valve head thickness
2. 45
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.
Item Standard Limit
Valve stem
Intake
5.965 – 5.980 mm
(0.2348 – 0.2354 in.)
–
diameter
Exhaust
5.940 – 5.955 mm
(0.2339 – 0.2344 in.)
–
Valve guide
I.D. In &
Ex
6.000 – 6.012 mm
(0.2362 – 0.2367 in.)
–
Stem-to-
guide
Intake
0.020 – 0.047 mm
(0.0008 – 0.0018 in.)
0.07 mm
(0.0027 in.)
guide
clearance
Exhaust
0.045 – 0.072 mm
(0.0018 – 0.0028 in.)
0.09 mm
(0.0035 in.)
Valves
Remove all carbon from valves.
Inspect each valve for wear, burn or distortion at its face and stem
and, as necessary, replace it.
Measure thickness of valve head. If measured thickness exceeds
limit, replace valve.
Item Standard Limit
Intake 1.0 mm (0.039 in.) 0.6 mm (0.023 in.)
Exhaust 1.2 mm (0.047 in.) 0.7 mm (0.027 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, re-
place valve.
Limit on valve head radial runout:
0.08 mm (0.003 in.)