🛠️ YZ250 YZ 250 72mm Big Bore Ported Cylinder + Machined Head – Complete Top End Kit (2001–2024)

Looking to boost your YZ250’s power? This 72mm Big Bore Top End Kit is built to perform. Featuring a Stage 2 ported cylinder and a machined head designed specifically for big bore use, this complete setup is ideal for high-compression, race-fueled, or big power builds. Includes everything you need to replace your entire top end with premium components.

✅ What’s Included:

• 72mm Stage 2 ported big bore cylinder

• Wiseco or Wossner 72mm forged piston

• Nitrided piston rings

• Armorglide-coated piston skirt

• Chrome wristpin + circlips

• Powervalve machined to match 72mm bore

• Cylinder head machined for 72mm big bore

• Wristpin bearing

• Spark plug

• Head stud kit

• Maxlock cylinder-to-case allen head stud kit

📦 Fitment:

Fits ALL 2001 and newer Yamaha YZ250 2-stroke models, including:
2001–2024 Yamaha YZ250 & Team Yamaha Editions

🛡️ Warranty Info:

We stand behind all parts 100%. Every component has been tested extensively and performs when installed and tuned properly.

⚠️ This is NOT a DIY kit. Engine assembly requires precision, specialty tools, and experience. Most failures are due to incorrect installation, break-in, or tuning.

• Stud Warranty: If a head stud fails during use (not during installation), a replacement stud kit will be provided. Studs must be returned for inspection.

• Cylinder Warranty: If your cylinder fails from a manufacturing issue unrelated to misuse, tuning, or install error, we will repair or replace it at no cost.