Suzuki GW250, Руководство по обслуживанию

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3-30 ENGINE
• If the seat width
W
measured exceeds the standard value or
seat width is not uniform, reface the seat using the seat cutter.

Valve seat width
W
:
Standard (IN. & EX.): 0.9 – 1.1 mm (0.035 – 0.043 in)
VALVE SEAT SERVICING
• The valve seats
1
for both the intake valves and exhaust
valves are machined to three different angles. The seat con-
tact surface is cut at 45°.
NOTE:
After servicing the valve seats, be sure to check the valve clear-
ance after the cylinder head has been reinstalled. (

2-8)
• Clean and assemble the head and valve components. Fill the
intake and exhaust ports with gasoline to check for leaks.
• If any leaks occur, inspect the valve seat and face for burrs or
other things that could prevent the valve from sealing.

INTAKE EXHAUST
Seat angle 30°, 45° 15°, 45°
Seat width 0.9 – 1.1 mm (0.035 – 0.043 in)
Valve diameter 27.0 mm (1.06 in) 22.5 mm (0.89 in)
Valve guide I.D. 5.000 – 5.012 mm (0.1969 – 0.1973 in)
* The valve seat contact area must be inspected after
each cut.
* Do not use lapping compound after the final cut is
made. The finished valve seat should have a velvety
smooth finish but not a highly polished or shiny fin-
ish. This will provide a soft surface for the final seat-
ing of the valve which will occur during the first few
seconds of engine operation.
Always use extreme caution when handling gasoline.
INTAKE
EXHAUST