Piston, Rings And Connecting Rod; Piston; Rings - Tecumseh VLV Technician's Handbook

PISTON, RINGS AND CONNECTING ROD

PISTON MEASUREMENTS ARE TAKEN AT
BOTTOM OF SKIRT 90 0
1ST COMPRESSION RING
2ND COMPRESSION RING
NOTE: EMISSION COMPLIANT
VLV USES THIS RING PACKAGE
PISTON. Before removing piston, clean any carbon from
the top of the cylinder bore to prevent ring breakage
when removing the piston. Push the rod and piston out
through the top of the cylinder.
Oversize pistons are identified by the size imprinted on
the piston as shown. Check the piston for wear by
measuring at the bottom of the skirt 90
pin hole. Clean the carbon from the piston ring grooves,
install new rings and measure side clearance.
Tolerances are listed in the table of specifications (page
40).
Replace rings in sets and always stagger ring gaps.
When in stalling new rings, deglaze cylinder wall, using
a commercially available deglazing tool.
Use a ring expander to remove and replace rings. Do
not spread the rings too wide or breakage will result.
The top compression ring will have a chamfer on the
inside edge. The ring must be installed with the chamfer
up.
To check ring end gap, place ring squarely in center of
ring travel area. Using the piston to push the ring down
into the cylinder at least one inch.
Check ring gap on new ring to determine if cylinder
should be rebored to take oversize parts. See Table of
Specifications (page 40).
www.SmallEngineDiscount.com
Chapter 8
INDICATES .010
OVERSIZE PISTON
FROM WRIST PIN HOLE
SIDE CLEARANCE
3RD OIL CONTROL RING
BARREL FACED TOP RING
SCRAPER RING
OIL CONTROL RING
from the wrist
o
Not For Resale
CYLINDER
CONNECTING RODS. Match marks on connecting
rods must always align and must face outward toward
the mechanic when installed in an engine.
MATCH MARKS
A new piston can be installed on to the connecting rod
in either direction.
If the old piston is reused, install the piston to the
connecting rod so that the piston will be in the same
position when reinstalled in the engine.
If it is necessary to replace the connecting rod be sure
to mark the valve side of the piston.

PISTON

PISTON RING
MATCH MARKS
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