959
Model Years Compression
Ratio
Stock
Engine
Bore x
Stroke
Bore
Size
Piston Type
and Coatings
Cylinder and Machining
Requirements
Top End
Kit
MTV # Single Piston MTV # Ring Set MTV # Piston
Pin
MTV # Circlip MTV # Top End
Bearing
MTV #
Yamaha 2-Stroke
YZ125 76-82 56.0 56.0 Deglaze / Hone 2205CS 316-2689 S270 316-3106 CW16 316-1903 B1016 316-7016
x 56.5 Bore & Hone 435M05650 316-1561 2224CS 316-2695
50.0 57.0 Bore & Hone 435M05700 316-1563 2244CS 316-2698
57.5 Bore & Hone 2264CS 316-2701
YZ125 1983 56.0 56.0 Deglaze / Hone 2205CS 316-2689 S270 316-3106 CW16 316-1903 B1016 316-7016
x 57.5 Bore & Hone 2264CS 316-2701
50.0
YZ125 1984 56.0 56.5 Deglaze / Hone 512M05650 316-1575 2224CS 316-2695 S270 316-3106 CW16 316-1903 B1016 316-7016
x 57.0 Bore & Hone 2244CS 316-2698
50.0 57.5 Bore & Hone 2264CS 316-2701
YZ125
* Power Valve must be modified for
58mm and larger
1985 56.0 57.0 Deglaze / Hone 2244CS 316-2698 S270 316-3106 CW16 316-1903 B1016 316-7016
x 58.0 Bore & Hone 521M05800 316-1588
50.0
YZ125
* Power Valve must be modified for
57mm and larger
86-88 56.0 56.0 Pro-Lite Deglaze / Hone PK1809 316-3815 559M05600 316-1597 2205CS 316-2689 S514 316-3160 CW16 316-1903 B1016 316-7016
x 56.5 Bore & Hone PK1805 316-3811 2224CS 316-2695
50.0 57.0 Bore & Hone PK1806 316-3812 559M05700 316-1601 2244CS 316-2698
57.5 Bore & Hone 2264CS 316-2701
58.0 Bore & Hone
YZ125 1989 56.0 56.0 Pro-Lite Deglaze / Hone S270 316-3106 CW16 316-1903 B1016 316-7016
x 56.5 Bore / Replate 2224CS 316-2695
50.0 57.0 Bore / Replate 582M05700 316-1609 2244CS 316-2698
YZ125 90-92 56.0 56.0 Pro-Lite Deglaze / Hone 2205CS 316-2689 S514 316-3160 CW16 316-1903 B1016 316-7016
x 56.5 Bore / Replate 2224CS 316-2695
50.7 57.0 Bore / Replate 594M05700 316-5461 2244CS 316-2698
YZ125 1993 56.0 56.0 Pro-Lite Deglaze / Hone 2205CS 316-2689 S514 316-3160 CW16 316-1903 B1016 316-7016
x 56.5 Bore / Replate 2224CS 316-2695
50.7 57.0 Bore / Replate PK1803 316-3809 2244CS 316-2698
YZ125 94-96 54.0 54.0 Pro-Lite Deglaze / Hone PK1700 316-3732 647M05400 316-1829 2126CS 316-2671 S514 316-3160 CW16 316-1903 B1016 316-7016
x 54.5 Bore / Replate PK1701 316-3733 647M05450 316-1831
54.5 55.0 Bore / Replate 2165CS 316-2683
56.0 Bore / Replate PK1703 316-3735 647M05600 316-0099 2205CS 316-2689
YZ125 1997 54.0 54.0 Pro-Lite Deglaze / Hone 693M05400 316-1808 2126CS 316-2671 S467 316-3138 CW15 316-1902 B1038 316-7038
x
54.5
YZ125 97-04 54.0 54.0 ElectraCoated Deglaze / Hone 765M05400 379-5462 2126CS 316-2671 S632 316-3187 CW15 316-1902 B1038 316-7038
x 56.0 Racers Choice Bore / Replate 97-00
54.5 GP Series
ArmorGlide B1001 316-7001
01-04
No Intake
Window
Pinned on
Centerline
YZ125 97-04 54.0 54.0 Flat Top Deglaze / Hone 762M05400 379-5410 2126CSA 316-0274 S632 316-3187 CW15 316-1902 B1038 316-7038
x 56.0 Conversion Bore / Replate 762M05600 379-5411 97-00
54.5 ArmorGlide
B1001 316-7001
01-04
No Intake
Window
Pinned on
Centerline
WISECO PISTONS (CONT.)