Piston diameter
Using a micrometer, measure the piston outside diameter at 20 mm (0.79 in) (A) from the piston skirt end.
If the measurement is less than the limit, replace the piston.
Piston diameter:
- Service Limit:
- 80.88 mm (3.184 in)
- at 20 mm (0.79 in) from the skirt end
- 09900-20204: Micrometer (75-100 mm)
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Piston-to cylinder clearance
As a result of the previous measurement, if the piston-to-cylinder clearance exceeds the service limit, rebore the cylinder and use an oversize piston or replace both the cylinder and piston.
Piston-to-cylinder clearance:
- Standard: 0.055-0.065 mm (0.0022-0.0026 in)
Piston-ring-to-groove clearance
Measure the side clearances of the 1st and 2nd piston rings using the thickness gauge.
If any of the clearances exceed the limit, replace both the piston and piston rings.
Piston-ring-to-groove clearance:
- Service Limit (1st): 0.18 mm (0.0071 in)
- Service Limit (2nd): 0.15 mm (0.0059 in)
![](https://motoinstruction.ru/img/suzuki/14/119997.jpg)
Piston ring groove width:
- Standard (1st): 1.21-1.23 mm (0.0476-0.0484 in)
- Standard (2nd): 1.01-1.03 mm (0.0398-0.0406 in)
- Standard (Oil): 2.01-2.03 mm (0.0791-0.0799 in)
Piston ring thickness:
- Standard (1st): 1.17-1.19 mm (0.0461-0.0469 in)
- Standard (2nd): 0.97-0.99 mm (0.0382-0.0390 in)
- 09900-20803: Thickness gauge
- 09900-20205: Micrometer (0-25 mm)
![](https://motoinstruction.ru/img/suzuki/14/119998.jpg)
Piston ring free end gap and piston ring end gap
Measure the piston ring free end gap using vernier calipers.
Next, fit the piston ring squarely into the cylinder and measure the piston ring end gap using the thickness gauge.
If any of the measurements exceed the service limit, replace the piston ring with a new one.
Piston ring free end gap:
- Service Limit (1st) : 7.6 mm (0.30 in)
- Service Limit (2nd): 8.8 mm (0.35 in)
- 09900-20102: Vernier calipers
![](https://motoinstruction.ru/img/suzuki/14/119999.jpg)
Piston ring end gap:
- Service Limit (1st): 0.70 mm (0.028 in)
- Service Limit (2nd): 0.70 mm (0.028 in)
- 09900-20803: Thickness gauge
![](https://motoinstruction.ru/img/suzuki/14/120000.jpg)
Oversize piston ring
The following two types of oversize piston rings are used.
They bear the following identification numbers.
SIZE | 1st | 2nd |
STD | NIL | NIL |
0.5 mm O.S. | 50 | 50 |
![](https://motoinstruction.ru/img/suzuki/14/120001.jpg)
Oversize oil ring
The following two types of oversize oil rings are available as optional parts.
They bear the following identification marks.
SIZE | COLOR | |
SIDE RAIL | SPACER | |
STD | NIL | RED |
0.5 mm O.S. | BLUE | BLUE |
Measure the outside diameter to identify the size.
![](https://motoinstruction.ru/img/suzuki/14/120002.jpg)
(1) Oil ring spacer; (A) Paint
Piston pins and pin bore
Measure the piston pin bore inside diameter using the small bore gauge.
If the measurement is out of specifications replace the piston.
Piston pin bore I.D.
- Service Limit: 20.030 mm (0.7886 in)
- 09900-20602: Dial gauge (1/1000 mm)
- 09900-22403: Small bore gauge (18-35 mm)
![](https://motoinstruction.ru/img/suzuki/14/120003.jpg)
Measure the piston pin outside diameter at three positions using the micrometer.
If any of the measurements are out of specification, replace the piston pin.
Piston pin O.D.
- Service Limit: 19.98 mm (0.7866 in)
- 09900-20205: Micrometer (0-25 mm)
![](https://motoinstruction.ru/img/suzuki/14/120004.jpg)