• Durability, longevity and increased horsepower
• Innovative forging design and piston skirt provide maximum horsepower and torque
• Lightweight wrist pins enable faster revs and quicker throttle response
• Contain all the necessary components for overboring or rebuilding your top end
• Cylinder sleeves must be purchased separately


Included Items:
(1) 643M04700 piston kit
(1) B1012 top end bearing
(1) W5221 top end gasket set

NOTE: Cylinder sleeving or replating required for oversizes

Our pistons, rings and kits are sold by application and bore size. Please note that STANDARD and OVERSIZES are not indicated. To get the correct part, you must know the standard bore size to make sure you are ordering either the standard or correct amount of oversize that you need. If you have any questions, please call Technical Service.

(1) Piston

(1) Wrist pin 

(1) Top ring

(2) Cir-clips

(1) 14x18x16.2mm Top end bearing

(1) Joint gasket

(1) Reed valve gasket

(1) O-ring

(1) Cylinder gasket

(1) Cylinder head gasket

Instructions