Piston Pin Inspection; Piston Ring Removal And Inspection - Yamaha V star 1100 Owner's Manual

ENGINE TOP END
128
129

Piston Pin Inspection

1. Clean the piston pin in solvent and dry it thor-
oughly.
2. Inspect the piston pin for chrome flaking or
cracks. Replace the pin if necessary.
3. Measure the outside diameter of the piston pin
with a micrometer (Figure 126). If the measure-
ment is outside the range specified in Table 2, re-
place the piston pin.
130
4. Measure the inside diameter of the piston pin
bore in the piston with a small bore gauge (Figure
127).
5. Calculate piston pin-to-piston clearance by sub-
tracting the piston pin outside diameter from the
piston pin bore inside diameter. If the clearance is
outside the range specified in Table 2, replace the
piston pin (if the piston bore inside diameter is
within specification).
6. Oil the piston pin and install it in the connecting
rod. Slowly rotate the piston pin, and check for ra-
dial and lateral play (Figure 128). If there is play,
the connecting rod should be replaced (if the piston
pin outside diameter is within specification). In-
spect the connecting rod as described in Chapter
Five.

Piston Ring Removal and Inspection

A three-ring assembly is used with each piston.
The top and second rings are compression rings.
The lower ring is an oil control ring assembly (con-
sisting of two ring rails and an expander spacer).
WARNING
The edges of all piston rings are very
sharp. Be careful when handling them
to avoid cutting fingers.
1. Remove the compression rings with a ring ex-
pander tool or by spreading the ends with your
thumbs just enough to slide the ring up over the pis-
ton (Figure 129). Repeat for the remaining rings.
2. Carefully remove all carbon build-up from the
ring grooves with a broken piston ring (Figure
130). Do not remove aluminum material from the
ring grooves. This will increase ring side clearance.
127
4