Wiseco 4440M07550 Forged Piston Kit Oversize Honda - 75.50mm 1.50mm 12 1 TRX250X

The Wiseco 4440M07550 is a forged piston kit designed for the Honda TRX250X ATV. This kit features a 75.50mm bore diameter — a 1.50mm oversize — and delivers a high 12:1 compression ratio, making it an ideal choice for rebuilds using a bored or sleeved cylinder. The stroke measures 57.3mm, and the kit is built around Wiseco's proven 2973XC ring set specification.

Key Features:

• Aerospace-grade forged aluminum construction — forging compresses molecular grain structure for superior strength, impact resistance, and fatigue resistance compared to cast alternatives
• 75.50mm bore / 1.50mm (.060") oversize — designed for use in bored cast iron cylinders or resleeved chrome, Nikasil, and boron composite cylinders
• 12:1 compression ratio — optimized for improved power output in the TRX250X four-valve 250cc engine
• ArmorGlide skirt coating — permanently bonded dry film lubricant reduces friction and helps quiet piston operation throughout the life of the part
• Diamond-turned CNC finish — precision machining ensures consistent sizing with no variation, compatible with cast iron, chrome, Nikasil, and boron composite cylinder bores
• USA manufactured — all forge tooling and manufacturing processes are completed in-house in the USA, from raw bar stock through finished skirt coating
• Pressure seal groove — prevents gas buildup below the top compression ring to maximize ring seal and maintain compression

Kit Includes:

• 1x Forged piston
• 1x Piston ring set (2973XC)
• 1x Wrist pin
• 2x Circlips

Wiseco is the only U.S.-based manufacturer that produces powersports pistons exclusively through the forging process. Each piston is engineered using 3D design techniques and finite element modeling to optimize the strength-to-weight ratio for each specific application. This kit is a direct upgrade for TRX250X engines requiring a bore job, providing the durability and performance that cast OEM-style pistons simply cannot match.