Honda CB900F Service Manual page 208

VALVE/VALVE GUIDE
CYLINDER HEAD/VALVES
Check t hat t he va lve m oves smoothly in th e g uide.
Inspect each va lve fo r bendi ng, burning o r abnorma l
stem wear.
Check valve movement in t he gu ide, measure and
reco rd each va lve stem 0 .0 .
SERVICE LIMITS:
IN: 4.465 mm (0.1758 in )
EX: 4.455 mm (0.1754 in)
Ream the guides to rem ove any carbon deposits
before checking clea rances.
Insert the reamer from the combustion chamber side
of the head and always rot at e the reame r clockwise.
TOOL:
Valve guide reamer, 4.508 mm 07HMH-ML0010l
VALVE GUI DE REA ME R
Reface the valve
seats whenever
the valve
guides are
replaced
(page 8-17),
Measure and record each valve gu ide 1.0.
SERVICE LIMIT: IN/EX: 4.540 mm 10.1787 inl
Subt ract each va lve stem 0 .0 . from t he correspond -
ing g uide I.D. to obta in t he stem -ta-g uide clea rance.
SERVICE LIMITS:
IN: 0.075 mm (0.0030 in)
EX: 0.085 mm (0.0033 in)
If the stem-ta-guide clearance is out of standard.
determine if a new gu ide with standard dimensions
would br ing the clea rance within tolerance. If so,
replace any guides as necessary and ream to fit.
If the stem -to-guide clearance is out of stand ard with
the new guides, replace the valves and gu ides.
8-15