Connecting Rods - Tecumseh ECV100 - 120 Technician's Handbook

Use a ring expander to remove and replace the rings. Do
not spread the rings too wide or breakage will result.
If the top compression ring has an inside chamfer, this
chamfer must face UP. The second compression ring will
have either an inside chamfer or an outside notch. The rule
to follow is an inside chamfer always faces up. An outside
notch (diag. 31) will face down or towards the skirt of the
piston.
The oil control ring can be installed with either side up. The
expander (if equipped) end gap and the ring end gap should
be staggered.
Emission Rings
Used on TVS, LEV, H35, VLV, HM80 and TVXL195
engines that comply with emission standards. These rings
have a narrower width and a different profile (barrel faced).
Barrel faced rings may be installed in either direction. The
underside of the oil control ring utilizes a coil type expander.
These rings conform better to the cylinder allowing for better
oil control by wiping the cylinder wall cleaner. The coiled
expander ring helps create a more uniform load on the
cylinder wall which gives a more consistent distribution of
oil. NOTE: The use of these rings on a standard non-
emission piston will cause ring breakage due to its wider
ring grooves.

Connecting Rods

Some engine models have offset piston pins (not centered)
to centralize the combustion force on the piston. Engine
models LAV50, HM70, HM80, HHM80, HM100,
TVM170,195, 220, have offset pistons. When installing the
connecting rod to the piston it is imperative that the rod be
installed correctly. The piston used on these models will
have either an arrow stamped above the piston pin hole, a
number cast on the inside of the piston skirt or an arrow
stamped on the top of the piston (diag. 32 & 33). All other
engine models use a centered piston pin. If the piston does
not have an arrow or number cast inside, the piston can be
installed in either direction on the connecting rod. On all
engine models, the match marks on the connecting
rod must align and face out when installing the
assembly in the engine (diag. 34 & 35).
The arrow on the top of the piston must point toward the
valves when installing it in the cylinder (diag. 33). The inside
casting number (if present) must face toward the long side
of the connecting rod. If there is an arrow on the side of the
piston, the arrow must point toward the short side of the
connecting rod. (diag. 32).
On horizontal shaft engines, oil dippers are attached to
the bottom connecting rod bolt. Some engines have the oil
dipper cast in the rod cap. Consult the specification chart
for the proper rod bolt torque when installing the cap. The
rod bolts should be torqued in 50 inch pound (5.5 Nm)
increments until the specified torque is achieved.
34
30
31
32
33
35
83