Suzuki RM-Z450 Owner's Service Manual page 114

• 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.
Always use extreme caution when handling gasoline.
VALVE SPRING
• Check the valve spring for proper strength by measuring its
free length and also by the force required to compress it.
• If the spring length is less than the service limit, or if the force
required to compress the spring does not fall within the range
specified, replace the spring.
" Valve spring free length:
Service limit (IN) : 34.0 mm (1.34 in)
(EX): 33.3 mm (1.31 in)
# 09900-20102: Vernier calipers
" Valve spring tension:
Standard (IN) : 119 – 137 N (12.1 – 14.0 kgf)/30.9 mm
(EX): 73 – 84 N (7.4 – 8.6 kgf)/30.9 mm
VALVE REASSEMBLY
• Install the valve spring seat.
• Apply MOLYBDENUM OIL SOLUTION to the stem seal 1,
and press-fit it into position.
% MOLYBDENUM OIL SOLUTION
Do not reuse the removed stem seal.
• Insert the valve, with its stem coated with MOLYBDENUM
OIL SOLUTION all around and along the full stem length with-
out any break.
When inserting the valve, take care not to damage the
lip of the stem seal.
% MOLYBDENUM OIL SOLUTION
& WARNING
(26.7 – 30.9 lbs/12.2 in)
(16.3 – 19.0 lbs/12.2 in)
CAUTION
CAUTION
CYLINDER HEAD, CYLINDER AND PISTON 6-17