67mm and Under OEM Yamaha Blaster Cylinder Kit

Description

OEM Yamaha Blaster Cylinder Kit for 67mm and Smaller Bores

Restore your Yamaha Blaster engine with a genuine OEM cylinder professionally prepared by Ken OConnor Racing. This kit is designed for Yamaha YFS200 Blaster engines requiring a cylinder with a finished bore size of 67mm or smaller.

Unlike a basic replacement cylinder, every cylinder is accurately measured and professionally honed using a torque plate. The torque plate simulates the distortion created when the cylinder head is installed and tightened. This helps establish a more accurate finished bore, proper piston clearance and consistent ring sealing after assembly.

Each kit includes a premium Wossner forged piston kit matched to the finished cylinder bore. Wossner pistons are known for their strength, durability and dependable performance in high-demand two-stroke engines.

What Is Included?

• Genuine OEM Yamaha Blaster cylinder
• Finished bore size of 67mm or smaller
• Wossner forged piston kit
• OEM Yamaha top end gasket set
• New cylinder studs
• Ten new flange nuts
• New top end wrist-pin bearing
• Professional torque-plate honing
• Final torque testing and inspection

Professionally Prepared by Ken OConnor Racing

Proper cylinder preparation is critical to the performance and service life of a two-stroke engine. The cylinder bore must be round, straight and correctly sized for the supplied piston. Incorrect piston-to-cylinder clearance can cause excessive noise, poor ring sealing, premature wear or piston failure.

Ken OConnor Racing prepares each cylinder using professional engine-machining procedures. The cylinder and piston are measured to establish the proper operating clearance, and the bore is finished to promote correct ring seating and oil retention.

This is a complete, matched cylinder and piston package—not a collection of unrelated components that must be measured and corrected before assembly.

Available Porting Options

Choose the cylinder in standard form or add professional porting to improve your Blaster’s power delivery.

No Porting

The best choice for a stock-style rebuild or riders who want dependable factory-style power characteristics.

Fast Trail Porting

Designed to produce stronger, more responsive performance while retaining a broad and manageable trail-riding powerband.

Aggressive Trail Porting

Provides a more substantial performance increase for modified engines and riders looking for a harder-hitting powerband.

Engine performance will also depend on the exhaust system, carburetor jetting, intake setup, reeds, compression, ignition and other modifications.

Fitment

Fits 1988–2006 Yamaha YFS200 Blaster models when the required finished cylinder bore is 67mm or smaller. Always confirm your engine configuration and required bore size before ordering.

If your engine requires a bore larger than 67mm, choose the 67.5mm and Over OEM Blaster Cylinder instead.

For an OEM cylinder fitted with a new sleeve, see the 66mm OEM Sleeved Cylinder Kit.

Order a Ready-to-Assemble Blaster Cylinder Kit

This OEM Yamaha Blaster cylinder kit gives you properly matched components prepared by an experienced engine machine shop. Select your preferred porting option and receive a cylinder package that is ready for careful installation and final engine assembly.