TOHATSU BFT 250A, Service Manual

Page: 402 / 639

14-34
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CYLINDER HEAD
VALVE FACE/STEM O.D.
Inspect each valve face [1] for pitting, wear, or
irregularities.
Inspect each valve stem for bending or abnormal stem
wear. Replace the valve if necessary.
Measure and record each valve stem O.D.
Replace the valves if their O.D. is smaller than the
service limit.
VALVE GUIDE I.D.
Using the valve guide reamer (special tool), ream the
valve guides to remove any carbon deposits before
measuring.
• Turn the special tool (valve guide reamer, 5.5 mm)
clockwise, never turn it counterclockwise. Continue
to turn it clockwise as you lift it from the valve guide.
Measure and record each valve guide I.D.
Replace the guides if they are over the service limit
(page 14-42).
STANDARD:
IN: 5.485 – 5.495 mm (0.2159 – 0.2163 in)
EX: 5.450 – 5.460 mm (0.2146 – 0.2150 in)
SERVICE LIMIT:
IN: 5.455 mm (0.2148 in)
EX: 5.420 mm (0.2134 in)
[1]
TOOL:
Valve guide reamer, 5.5 mm [1] 07HAH-PJ7A100
[1]
STANDARD:
IN/EX: 5.515 – 5.530 mm (0.2171 – 0.2177 in)
SERVICE LIMIT:
IN/EX: 5.55 mm (0.219 in)