User Manual

50 SENR9977
Testing and Adjusting Section
Basic Engine
i01889476
Piston Ring Gr oo ve - Inspect
Inspect the Piston and the Piston
Rings
1. Check the piston for wear and other damage.
2. Check that the piston rings are free to move in the
grooves and that the rings are not broken.
Inspect the C learance of the Piston
Ring
1. Remove the piston rings and clean the grooves
and the piston rings.
g00905732
Illustration 55
(1) Feeler gau ge
(2) Piston ring
(3) Piston g rooves
2. Fit new piston rings (2) in the piston grooves (3).
3. Check the clearance for the piston ring by placing
a suitable feeler gauge (1) between the piston
groove (3) and the top of piston ring (2). Refer
to Specifications, “Piston and Rings” for the
dimensions.
Note: Some pistons have a tapered top groove and
the piston ring
is wedged. The clearance for the top
piston ring cannot be checked by the above method
when this occurs.
Inspect the Piston Ring End G ap
g00983549
Illustration 56
(1) Piston ring
(2) Cylinder ring ridge
(3) Feeler gauge
1. Clean all carbon from the top of the cylinder bores.
2. Placeeachpistonring(1)inthecylinderborejust
below the cylinder ring ridge (2).
3. Use a suitable feeler gauge (3) to measure the
piston ring end gap. Refer to Specifications,
“Piston and Rings” for the dimensions.
Note: The coil spring must be removed from the oil
control ring before the gap of the oil control ring is
measured.
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Conne ctin g Rod - Inspec t
This procedure determines the following
characteristics of the connecting rod:
•
The distortion of the connecting rod
•
The parallel alignment of the bores of the
connecting rod