10 Best Pit Bike Engines 2025 in the United States

The TDPRO Full Set of Lifan 125cc Engine is a semi-automatic 4-stroke motor designed for trail bikes, including models like CT70, 90, 110, and 125. This engine features a 125cc displacement, which offers a decent balance of power and efficiency for recreational and light off-road use. It comes with an automatic clutch system and a 4-speed transmission (N-1-2-3-4), allowing for smooth gear transitions and ease of use, especially for inexperienced riders.

The package includes essential components like a carburetor kit, exhaust pipe kit, chain and sprocket, throttle kit, and wiring harness, which makes it a comprehensive replacement or upgrade option for various popular bikes. One of its standout features is the standardized mounting points, ensuring compatibility with various monkey/dax/supercub/pitbike models. However, users are advised to check the mounting hole spacing before purchasing to avoid compatibility issues.

With adequate power for most trail and dirt bikes, this engine is cooled by air, which is generally sufficient for typical usage but may not be ideal for very long, high-intensity rides. This engine is a solid choice for those looking to replace or upgrade their pit-bike engine, but it might not suit those seeking maximum performance or advanced cooling systems.

The WPHMOTO Lifan 150cc 4 Stroke Oil Cooled Racing Engine is a solid choice for riders looking to upgrade or replace the engine on popular small dirt bikes like the XR50, CRF50, and similar models. Its 150cc displacement and 4-stroke single-cylinder design offer a good balance of power and reliability. With a horsepower of about 9 kW (around 12 hp) at 7500 rpm and a torque of 11 Nm at 5000 rpm, it provides enough punch for typical pit bike use, including racing and trail riding.

The engine features a 4-speed manual transmission with a manual clutch, giving the rider full control over shifting, which is preferred for a more engaging riding experience. An important feature is the oil cooling system, which helps keep the engine temperature stable during longer or harder rides, potentially extending engine life compared to air-cooled alternatives. Additionally, this engine kit includes a carburetor and wiring harness for easier installation.

There are a few downsides to consider. The engine is slightly heavy compared to some air-cooled models, which might affect bike handling for very young or small riders. It also has a relatively high top speed rpm, so it may require tuning for optimal performance depending on your specific bike setup. Some buyers noted that installation instructions could be clearer, so a basic mechanical knowledge or professional help might be needed. This engine represents a reliable and powerful upgrade for pit bike enthusiasts who want a durable 4-stroke engine with efficient cooling and solid performance.

The ZXTDR Lifan 150cc engine is a solid choice for those looking to replace or upgrade their XR50, CRF50, Kawasaki, or similar dirt pit bike engines. With a 150cc displacement and a 4-stroke, 4-speed manual transmission, it offers a good balance of power and control for dirt bike riders. The engine is oil-cooled, which helps with temperature management during rides, a key feature for maintaining performance and durability.

The kit includes everything needed for installation, such as the engine itself, starter, gear lever, manifold kit, CDI box, and ignition coil, making it relatively straightforward to swap out an old engine without needing extra parts. This can be especially appealing for users who want a direct replacement without complicated modifications. The product has a modest customer rating of around 3.2 out of 5 stars, indicating some users have experienced issues or limitations. Its rank shows it is a moderately popular option within replacement engine kits but not a top seller.

Horsepower is not explicitly stated, but a 150cc four-stroke engine generally provides enough power for casual off-road riding and beginner to intermediate riders. This engine suits riders who want a practical and compatible upgrade for common pit bikes, especially if ease of installation and parts compatibility are important. Those seeking high-end racing performance might want to consider more specialized options.