TOHATSU NB-1000 Service Manual page 112

SECTION 4
7. Measure and record the diameter of each cylinder
28 29
bore and the outside diameter of its respective piston.
Subtract the values to calculate the piston clearances. lf any bore
diameter or piston clearance exceeds the specified limit, the cylinder
must be professionally bored oversize for use with an oversize piston.
Model
2.5 / 3.5
5
8 / 9.8
9.9 / 15
18
25 / 30
40
8. Complete the following inspection for new or used piston
30
ring sets. Inspect each ring separately:
• Place ring in its respective cylinder bore.
• Use a piston to square the ring in the bore.
• Use the thickness gauge set (Part No. 353-72251-0) to measure
the ring end gap.
4-32
29
T2027
Standard
Bore Diameter
in [mm]
1.85 [47]
2.16 [55]
1.97 [50]
2.16 [55]
2.36 [60]
2.68 [68]
2.76 [70]
T2028
Standard
Piston Clearance
in [mm]
0.0024 - 0.0035
[0.06 - 0.09]
0.008 - 0.020
[0.02 - 0.05]
0.008 - 0.020
[0.02 - 0.05]
0.0020 - 0.0035
[0.05 - 0.09]
0.0020 - 0.0035
[0.05 - 0.09]
0.0024 - 0.0039
[0.06 - 0.10]
0.0020 - 0.0039
[0.05 - 0.10]
T1235
Repair Limit
Piston Clearance
in [mm]
0.006 or over
[0.15 or over]
0.006 or over
[0.15 or over]
0.006 or over
[0.15 or over]
0.006 or over
[0.15 or over]
0.006 or over
[0.15 or over]
0.006 or over
[0.15 or over]
0.006 or over
[0.15 or over]
1-/ 2-Cylinder