Axial play of the crankshaft
Use a dial gauge to measure the clearance between the thrust bearing and the crank arm by moving the crankshaft back and forth.
- Standard backlash: 0.10-0.26mm
- Limit play: 0.3 mm
If the measured value exceeds the specified limit, replace the thrust bearing with a new one and measure again. If the play is still significant, replace the crankshaft with a new one.
Connecting rod side clearance
Using a feeler gauge, measure the side clearance between the connecting rod and the crank arm.
- Standard: 0.20-0.35mm
- Limit: 0.4mm
If the measured clearance is greater than normal, replace the connecting rod with a new one and measure again. If the clearance is still significant, also replace the crankshaft.
Gap between piston and piston pin
Piston pin bore inner diameter
Measure the inside diameter of the piston pin bore using a bore gauge.
- Standard diameter: 21.993-22.005mm
Piston pin outer diameter
Using a micrometer, measure the outside diameter of the piston pin.
- Standard diameter: 21.989-22.001mm
Calculation of clearance between piston and piston pin
(Piston pin clearance) = (Piston pin hole diameter) - (Piston pin outer diameter) Standard clearance at 20°C: 0.002-0.006 mm
If the clearance is excessive, replace the piston and piston pin assembly.
When replacing the piston and piston pin assembly, select the components in accordance with section «Clearance between piston and cylinder».
Note: Pistons are installed complete with piston pins.
Piston ring side clearance
Using a feeler gauge, measure the clearance between the piston ring and the piston ring groove.
If clearance is abnormal, replace piston and/or piston ring.
Gaps, mm
Piston ring gap
Make sure the cylinder diameters are within specification. (See further section «Cylinder diameter»). Use a piston to push the piston ring to the middle of the cylinder and measure the gap in the lock.
Gaps, mm