- Balancer shaft runout
Out of specification → Replace the balancer shaft.
Balancer shaft runout limit 0.030 mm (0.0012 in).
![](https://motoinstruction.ru/img/yamaha/20/126782.jpg)
2. Check:
- Balancer shaft journal surfaces
- Bearing surfaces
Scratches/wear → Replace the balancer shaft.
3. Measure:
- Balancer shaft-journal-to-balancer shaftjournal-bearing clearance
Out of specification → Replace the balancer shaft journal bearings.
Journal oil clearance 0.012-0.043 mm (0.00050.0017 in).
Notice: Do not interchange the balancer shaft journal bearings. To obtain the correct balancer shaft-journal-to-balancer shaft-journalbearing clearance and prevent engine damage, the balancer shaft journal bearings must be installed in their original positions.
a. Clean the balancer shaft journal bearings, balancer shaft journals, and bearing portions of the crankcase.
b. Place the upper crankcase upside down on a bench.
c. Install the balancer shaft journal upper bearings "1" and the balancer shaft into the upper crankcase.
Align the projections "a" on the balancer shaft journal upper bearings with the notches "b" in the upper crankcase.
![](https://motoinstruction.ru/img/yamaha/20/126783.jpg)
d. Put a piece of Plastigauge® "1" on each balancer shaft journal.
Do not put the Plastigauge® over the oil hole in the balancer shaft journal.
![](https://motoinstruction.ru/img/yamaha/20/126784.jpg)
e. Install the balancer shaft journal lower bearings "1" into the lower crankcase and assemble the crankcase halves.
- Align the projections "a" of the balancer shaft journal lower bearings with the notches "b" in the lower crankcase.
- Do not move the balancer shaft until the clearance measurement has been completed.
![](https://motoinstruction.ru/img/yamaha/20/126785.jpg)
f. Tighten the bolts to specification in the tightening sequence cast on the crankcase. Refer to "Crankcase".
g. Remove the lower crankcase and the balancer shaft journal lower bearings.
h. Measure the compressed Plastigauge® width "a" on each balancer shaft journal. If the balancer shaft-journal-to-balancer shaft-journal-bearing clearance is out of specification, select replacement balancer shaft journal bearings.
![](https://motoinstruction.ru/img/yamaha/20/126786.jpg)
4. Select:
- Balancer shaft journal bearings (J1-J4)
- The numbers "A" stamped into the balancer shaft web and the numbers "B" stamped into the lower crankcase are used to determine the replacement balancer shaft journal bearing sizes.
- J1-J4 refer to the bearings shown in the balancer shaft illustration.
- If J1-J4 are the same, use the same size for all of the bearings.
For example, if the crankcase J1 and balancer shaft web J1 numbers are 6 and 2 respectively, then the bearing size for J1 is:
J1 (crankcase) - J1 (balancer shaft web) - 1 = 6 - 2 - 1 = 3 (brown)
Bearing color code:
- 0. White
- 1. Blue
- 2. Black
- 3. Brown
- 4. Green
- 5. Yellow
- 6. Pink
![](https://motoinstruction.ru/img/yamaha/20/126787.jpg)