- Crankshaft-pin-to-big-end-bearing clearance
Out of specification → Replace the big end bearings.
Crankshaft-pin-to-big-end-bearing clearance 0.034-0.058 mm (0.0013-0.0023 in). Limit 0.09 mm (0.0035 in).
The following procedure applies to all of the connecting rods.
Notice: Do not interchange the big end bearings and connecting rods. To obtain the correct crankshaft-pin-to-big-end-bearing clearance and prevent engine damage, the big end bearings must be installed in their original positions.
a. Clean the big end bearings, crankshaft pins, and the inside of the connecting rods halves.
b. Install the big end upper bearing into the connecting rod and the big end lower bearing into the connecting rod cap.
Align the projections "a" on the big end bearings with the notches "b" in the connecting rod and connecting rod cap.
![](https://motoinstruction.ru/img/yamaha/20/126758.jpg)
c. Put a piece of Plastigauge® "1" on the crankshaft pin.
![](https://motoinstruction.ru/img/yamaha/20/126759.jpg)
d. Assemble the connecting rod halves.
- Do not move the connecting rod or crankshaft until the clearance measurement has been completed.
- Lubricate the bolt threads with molybdenum disulfide oil.
- Make sure that the "Y" mark "c" on the connecting rod faces towards the left side of the crankshaft.
- Make sure that the characters "d" on both the connecting rod and connecting rod cap are aligned.
![](https://motoinstruction.ru/img/yamaha/20/126760.jpg)
e. Tighten the connecting rod bolts.
Refer to "Installing the connecting rod and piston".
f. Remove the connecting rod and big end bearings.
g. Measure the compressed Plastigauge® width on the crankshaft pin.
If the crankshaft-pin-to-big-end-bearing clearance is out of specification, select replacement big end bearings.
![](https://motoinstruction.ru/img/yamaha/20/126761.jpg)
2. Select:
- Big end bearings (P1-P4)
- The numbers "A" stamped into the crankshaft web and the numbers "1" on the connecting rods are used to determine the replacement big end bearings sizes.
- "pi"—"p4" refer to the bearings shown in the crankshaft illustration.
For example, if the connecting rod "P1" and the crankshaft web "P1" numbers are "5" and "2" respectively, then the bearing size for "P1" is:
"P1" (connecting rod) - "P1" (crankshaft) = 5 - 2 = 3 (brown).
Bearing color code:
- 1.Blue
- 2.Black
- 3. Brown
- 4.Green
![](https://motoinstruction.ru/img/yamaha/20/126762.jpg)