Wiseco 4890M10100 Forged Piston - CRF450R/X TRX450R 101mm 12.5 1 Kit

The Wiseco 4890M10100 is a high-performance forged piston kit engineered for Honda CRF450R, CRF450X, and TRX450R/X applications running a 12.5:1 compression ratio. Featuring a dished crown design optimized for 4-valve cylinder heads, this piston is manufactured to exacting tolerances for reliable power output in demanding off-road and motocross conditions.

Key Features:

• 101mm (4890M101) bore diameter — precision-machined for a consistent, controlled fit
• 12.5:1 compression ratio — performance-tuned dished crown for 4-valve head compatibility
• 19.19mm wrist pin — OEM-spec pin diameter for proper fitment
• Forged 2618 aluminum alloy — condensed grain structure aligned to part features for superior strength, impact resistance, and fatigue durability
• Proprietary skirt coating — reduces friction and wear for extended service life
• USA-manufactured forging tooling — all forgings produced in-house at Wiseco's Mentor, Ohio facility for complete quality control from raw material to finished part

Unlike brittle cast pistons that can fail catastrophically when material yield strength is exceeded, Wiseco's forged pistons offer a superior strength-to-weight ratio and the toughness required for high-performance motorsport environments. The aligned grain structure delivers measurably higher mechanical properties compared to castings, making this piston an ideal choice for riders who demand reliability under extreme racing conditions.

Specifications:

• Bore: 101.00mm (3.976 in)
• Compression: 12.5:1
• Crown: Dished, 4-valve
• Wrist Pin Diameter: 19.19mm
• OEM Cross-Reference: Honda CRF450R/X, TRX450R