YAMAHA R15 V1/V2 BIG BORE KIT 65MM BY NMW RACING

Key Components

1. Forged Piston: Unlike standard cast pistons, forged pistons are manufactured under extreme pressure, making them denser and more resistant to the high heat and stresses of a bored-out engine.

2. Cylinder Block: A high-quality sleeved or ceramic-coated block bored to exactly 65mm.

3. Piston Rings: High-tension rings designed to handle the increased surface area and cylinder pressure.

4. Gasket Kit: Includes a larger diameter head gasket and a base gasket.

   Performance Expectations

   • Power Output: With proper tuning, this kit can push the R15’s power toward the 20-24 hp range (depending on supporting mods like ECU and exhaust).

   • Torque: A substantial increase in low-end and mid-range torque, making the bike feel much “punchier” out of corners.

   • Top Speed: While top speed increases, the primary benefit is how much faster the bike reaches its limit.

   [!IMPORTANT] Supporting Mods Required: For a 65mm bore, it is highly recommended to upgrade your Fuel Injector (higher flow rate) and use a Programmable ECU (like NMW’s 8-map ECU) to prevent the engine from running lean, which can cause seizing.