Namura Standard Bore Top End Rebuild Kit Size C for Yamaha YZ450F 2020-2022 97mm

Namura Standard Bore Top End Rebuild Kit Size C for Yamaha

This top end rebuild kit for the 2020-2022 Yamaha YZ450F features a piston, rings, gasket set, and wrist pin to refresh 97mm bore performance.

Overview

The Namura Standard Bore Top End Rebuild Kit Size C is a complete overhaul set for the Yamaha YZ450F, delivering a cast piston, ring pack, gaskets, and wrist pin for a factory-spec rebuild. It targets the 97mm bore to restore compression and eliminate blow-by. This kit is ideal for riders performing routine top end service on their motocross machine.

Built For Performance

• Cast piston engineered for low expansion and stable clearances under heat
• High-tensile steel rings maintain consistent cylinder wall contact
• Full gasket kit includes head, base, and exhaust seals for leak-free assembly
• Wrist pin with hardened surface reduces wear at the rod and piston bore
• Verified 97mm size matches the OEM cylinder bore without machining

Fits These Machines

• for Yamaha YZ450F 2020-2022

On-The-Job Use

• Motocross practice and race days requiring a dependable top end replacement
• Engine rebuild after hours of high-rpm track use to prevent piston failure
• Restoring lost power from worn rings and piston
• Pre-season maintenance to ensure consistent performance across the season

Specs At A Glance

Good To Know

Q: Do I need to adjust piston-to-wall clearance with this kit? A: No, the Size C piston is pre-sized for a 97mm bore and follows OEM specifications, so no additional clearance work is required.

Q: Can I install this kit without removing the engine? A: The top end can be serviced with the engine in the frame, but the cylinder head and cylinder must be lifted to access the piston.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.