78
8. Mount the cylinder cover or flange with the
governor gear assembly installed to the
crankcase using dowel pins to position the
cover and a new gasket. Install the cover down
onto the crankcase and slightly rotate the
crankshaft to allow the governor gear to mesh.
Do not force. Apply a drop of blue Loctite 242
to the cover screw threads and tighten to the
specified torque.
On engines with ball bearings in the cover,
install a thrust washer (if applicable) over the
crankshaft, followed by the retaining ring.
On OHV 13.5 -17 engines, install the oil pump
drive shaft into the slot in the end of the
camshaft. Apply engine oil and install the oil
pump ring and rotor, followed by a new "O"
ring and the pump cover. Tighten the screws
to 50-70 inch pounds (5.5 - 8 Nm) torque.
9. Install the breather assembly.
10. Rotate the crankshaft to place the piston at
Top Dead Center (TDC) on the compression
stroke.
NOTE:
Always cut the valve seats, never only
lap the seats.
11. Pre-assemble the valves and spring
assemblies into the cylinder head on all engine
models
EXCEPT
OHM, OHSK80-130, OVM,
OVXL (diag. 65 on page 79). Use a small block
to support the valves tight to their seats while
placing the head on a flat surface. For models
OHH and OVRM, install the springs
(dampening coils toward the head) and
retainers on the valves and use fingers to
compress the springs until the notch in the
retainer is located in the notch in the valve
stem. Repeat the procedure for other valve.
For OHV models, place the springs
(dampening coils toward the head) over the
valve guide and place the valve caps on the
springs with the larger opening away from the
springs. Use spring compressor tool part #
670315A installed on a rocker arm stud, and
either turn the stud in or secure with a locking
nut as shown so about 1-1/2" (38.1 mm) of
the stud is exposed. Compress the spring and
install the valve retainers to lock the valve to
the valve cap. Repeat the procedure for other
valve.
Install the cylinder head using a new head
gasket. On OHV 11-13 models, place the push
rods in the block before installing the head
and head gasket. Tighten the head bolts in
the numbered sequence using 60 inch pound
(6.8 Nm) increments to the specified torque.
NOTE:
Tecumseh strongly recommends you
order a complete seal kit. Replace all "O" ring
and gaskets in kit.
RETAINERS HELD BY SPRING
TENSION AGAINST THE CAP
CAP
RETAINER
ROTOR
SHAFT
NOTE: INSTALL OIL PUMP AFTER THE SUMP IS ON
60
61
62
VALVE SPRING
COMPRESSOR TOOL
PART NO. 670315
63
ROTARY PUMP
RING
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