BRC YAMAHA 500cc CONVERSION KIT 1999-2025, BOLT IN 500CC CONVERSION

Yamaha 500cc conversion kit for 1999-2025 applications, developed as a bolt-in 500cc counterbalanced 2-stroke conversion based on the YZ250 platform. This conversion kit requires components from a donor Yamaha YZ250 engine from 1999-2025 and is designed to deliver strong motocross-focused performance with smooth, linear power delivery. It accepts donor YZ250 and YZ250X transmission components, remains kick-start compatible with a decompression button fitted to aid starting, and includes a dedicated exhaust pipe and silencer. It fits 2005-2051 aluminium frames without fabrication, while 1999-2004 steel frames require minor modification. The stock carburettor is stated to be the best fit for this package.

Features

• Bolt-in 500cc counterbalanced 2-stroke conversion

• Requires components from a donor Yamaha YZ250 engine

• Motocross-focused power delivery

• Pneumatic power valve system for linear, smooth power delivery

• Triple blade power valve for improved bottom-end performance

• Accepts donor Yamaha YZ250 and YZ250X transmission

• Kick-start compatible

• Decompression button fitted to make kick-starting easier

• Supplied with a purpose-built pipe and silencer to fit the bike

• Integral counterbalance shaft to reduce vibration

• Designed to use the stock carburettor

Specifications

• 499cc engine capacity

• 60+ hp

• 50+ ft-lb torque

Vehicle Fitments

• 2005-2025 Yamaha aluminium frame models

• 1999-2004 Yamaha steel frame models with minor modification