This powerful YX149 bare engine gen4 with a Z40 cam and 12v race stator is a great replacement part for your pitbike, c90 or monkey bike. It has been designed by ace racing and can produce up to 15bhp. The engine is in excellent working condition and is ready to be installed on your bike. The engine is part of the Trials & Motocross Bike Parts and Vehicle Parts & Accessories categories and is suitable for anyone looking to upgrade their bike's performance. The model/series is gen4 and the intended use is a replacement part. With this engine, you can enjoy a smoother ride and better acceleration.