Checking The Piston Pins; Checking The Big End Bearings - Yamaha YZF-R1P Service Manual

CONNECTING RODS AND PISTONS
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CHECKING THE PISTON PINS

The following procedure applies to all of the
piston pins.
1. Check:
• piston pin
Blue discoloration/grooves → Replace the
piston pin and then check the lubrication
system.
2. Measure:
• piston pin outside diameter a
Out of specification → Replace the piston
pin.
Piston pin outside diameter
16.991 ~ 17.000 mm
(0.6689 ~ 0.6693 in)
<Limit: 16.971 mm (0.6681 in)>
3. Measure:
• piston pin bore inside diameter b
Out of specification → Replace the piston.
Piston pin bore inside diameter
17.002 ~ 17.013 mm
(0.6694 ~ 0.6698 in)
<Limit: 17.043 mm (0.6710 in)>
4. Calculate:
• piston-pin-to-piston clearance
Out of specification → Replace the piston
pin and piston as a set.
Piston-pin-to-piston clearance =
Piston pin bore size –
Piston pin outside diameter
Piston-pin-to-piston clearance
0.002 ~ 0.022 mm
(0.00008 ~ 0.00087 in)
<Limit: 0.072 mm (0.00238 in)>

CHECKING THE BIG END BEARINGS

1. Measure:
• crankshaft-pin-to-big-end-bearing clearance
Out of specification → Replace the big end
bearings.
Crankshaft-pin-to-big-end-bear-
ing clearance
0.031 ~ 0.055 mm
(0.0012 ~ 0.0022 in)
ENG