Valves, Lifters, Springs And Seats; Valve Removal; Valve Seats; Valve Service - Tecumseh VLV Technician's Handbook

VALVES, LIFTERS, SPRING & VALVE SEATS
VALVES. Valves must be in good condition, proper
sealing and proper gap must be maintained for full
power, easy starting and efficient operation.

VALVE REMOVAL.

To remove valves, use a
commercially available valve spring compressor. Move
the lower cap, so it will slip off the end of the valve.
Clean all parts and remove carbon from valve heads
and stems. If valves are in usable condition, grind the
valve faces to a 45 angle. Replace valves if they are
o
damaged, distorted or if the margin is ground to less
than 1/32''.
MARGIN
1/32" MINIMUM
DIMENSION
STEM
VALVE SEATS. Valve seats are not replaceable. If
they are burned or pitted, they can be reground using a
grinding stone or valve seat cutter.
The recommended procedure to properly cut a valve
seat is to use the Neway Valve Cutting System, which
consists of three different degree-cutters. First, use the
60 cutter to clean and narrow the seat from the bottom
o
toward the center.
30
Chapter 11
45
o
FACE
EXHAUST
VALVE
46
o
INTAKE
VALVE
SEE SPECIFICATIONS
SECTION FOR DIMENSIONS
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BOTTOM
NARROWING
CUTTER
15
o
60
o
BOTTOM
NARROWING
Second, use the 31 cutter to clean and narrow the seat
o
from the top toward the center.
TOP
NARROWING
CUTTER
Ú
SEAT
Seats are ground at an angle of 46
SEAL CUTTER
Ú
SEAT
Valves are not identical. Make sure the valve marked
"EX" or "X" is installed in the exhaust valve location,
and the valve marked "I" is installed in the intake valve
location. If the valves are unmarked, the nonmagnetic
valve is installed in the exhaust valve location.
SEAT
46
o
31 o
, to a width of 3/64''.
o
31
o
46
o