Service manual

4-25
ENG
VALVES AND VALVE SPRINGS
2. Replace:
9
valve guide
NOTE:
To ease valve guide removal and installation,
and to maintain the correct fit, heat the cylinder
head to 100 ° C in an oven.
✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭✭
a. Remove the valve guide with the valve
guide remover
1
.
b. Install the new valve guide with the valve
guide installer
2
and valve guide remover
1
.
c. After installing the valve guide, bore the
valve guide with the valve guide reamer
3
to obtain the proper valve-stem-to-valve-
guide clearance.
NOTE:
After replacing the valve guide, reface the valve
seat.
✬✬✬✬✬✬✬✬✬✬✬✬✬✬✬✬✬✬✬✬✬✬✬✬
3. Eliminate:
9
carbon deposits
(from the valve face and valve seat)
4. Check:
9
valve face
Pitting/wear
→
Grind the valve face.
9
valve stem end
Mushroom shape or diameter larger than
the body of the valve stem
→
Replace the
valve.
5.Measure:
9
valve margin thickness
a
Out of specification Replace the valve.
Valve margin thickness
Intake: 0.5 – 0.9 mm
(0.0197 – 0.0433 in)
Exhaust: 0.5 – 0.9 mm
(0.0197 – 0.0433 in)
Valve guide remover (4.5 mm)
90890-04116
Valve guide installer (4.5 mm)
90890-04117
Valve guide reamer (4.5 mm)
90890-04118
http://mototh.com