03-06 WR450F WR 450F 98m Big Bore Kit +3 Cylinder 480cc Top End Rebuild Assembly
20001, 4785M09500, C3066, 71014-5, 5TA-11311-12-00, CR8EIX, 5TA-11311-00-00, 5TG-11633-10-00, 5TG-11603-00-00, 99999-03528-00, 99009-20500-00, 5TA-11181-00-00, 5TA-11351-00-00, 4FM-12213-00-00, 5TA-11311-01-00, 5TA-11311-02-00, 5TA-11311-10-00, 5TA-11311-11-00, 5TG-11631-00-00, 5TG-11633-00-00, 3KS-12213-00-00, 4BE-12213-00-00
⚡ 03–05 YZ450F / 03–06 WR450F 480 cc Big-Bore Top-End Rebuild Kit – 98 mm Nikasil Cylinder + Forged Piston + Cometic Gaskets ⚡
🛠️ Product Description
Unlock serious, reliable horsepower with this all-in-one 480 cc big-bore top-end rebuild package. The BPRATV 98 mm Nikasil-plated cylinder drops straight into your YZ450F or WR450F with no machining required — just bolt on and ride! Paired with a CP-Carrillo or JE forged piston*, plus a complete Cometic MLS gasket set, heavy-duty cam chain, and titanium head stud kit, this combo adds arm-wrenching torque while staying bullet-proof dependable on the track or trail.
✅ Key Features
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BPRATV 98 mm Nikasil Cylinder – precision-plated for top-tier wear resistance (1-year warranty)
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CP-Carrillo / JE / Wiseco Forged Piston – includes rings, wrist-pin & clips for race-grade durability
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Cometic Complete Top-End Gasket Kit – MLS head gasket engineered for big-bore compression
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BPRATV Talon Heavy-Duty Cam Chain – thicker side plates handle high-rev stress
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BPRATV Titanium Head Stud Kit – lightweight, stretch-resistant studs hold torque under heat
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Everything in the Box – arrives brand-new in original packaging, ready to install
| Advantage | What It Means for You |
|---|---|
| +3 mm / 480 cc Displacement | Massive torque jump & quicker pull out of corners |
| Nikasil vs. cast-iron sleeve | Cooler running, longer cylinder life |
| Forged, not cast piston | Survives high RPM abuse without skirt collapse |
| MLS head gasket | Secure seal under elevated combustion pressures |
| One-year warranty | Confidence that your investment is protected |
❓ FAQs
Will it fit my bike?
Yes! Direct fit for YZ450F (2003-2005) & WR450F (2003-2006)
Do I need special jetting or ECU changes?
A richer fuel setting is recommended to maximize the extra displacement and keep temps down.
Pump gas or race gas?
The kit’s piston works great on high-octane pump gas; race fuel unlocks full potential.
Can I install this myself?
If you’re comfortable with top-end service and have a torque wrench, you’re set. Otherwise, any experienced engine builder can handle the swap quickly.
Does it include instructions?
A detailed component checklist is provided; follow your factory service manual for specs.
