10 Best Bicycle Engine Kits 2025 in the United States

The Mahugde Upgraded 100cc Bicycle Engine Kit is designed to convert a regular 26" or 28" bicycle into a motorized bike, making riding faster and more exciting. It uses a 2-stroke gasoline engine that is air-cooled, which is common in lightweight motor kits and generally easy to maintain. The 100cc engine size provides a good balance of power for casual riders, while the single-speed chain-driven setup keeps things simple. Its fuel tank holds 0.53 gallons, allowing longer rides without frequent refueling, and it consumes fuel at a moderate rate around 0.66 gallons per 100 km. The kit supports a maximum rider weight of 440 lbs, making it suitable for most adults. The build quality is solid, featuring an aluminum engine body and iron fuel tank, with treatments to improve durability and ensure stable operation over time.

Noise and vibration levels are low for this type of engine, producing about 75 decibels, so it won’t be overly disruptive outdoors. Installation requires assembly, which might be a bit challenging if you’re not handy with bike mechanics, but it fits most standard mountain bikes with 26" wheels. One limitation is that it has only one speed, so hill climbing or very fast speeds might be limited compared to more advanced kits. Also, being a 2-stroke engine, it requires mixing oil with fuel and regular maintenance to keep it running well. This kit is a great choice if you want a straightforward, durable motor kit that boosts your bike’s speed and has decent range, especially for casual riders who don’t need complex gearing or electric power.

The TTONSUE Bicycle Motor Kit 100cc is a solid choice for those looking to convert a regular bike into a gasoline-powered one. Featuring a 2-stroke petrol engine, it promises a powerful ride with its 100cc engine size, suitable for various bike models including mountain, cruiser, chopper, and road bikes with 26" or 28" wheels. The kit includes all necessary parts for installation, including the engine, fuel tank, carburetor, exhaust muffler, and various cables, making it quite comprehensive.

One of its highlighted features is the 56mm bore cylinder which helps in better performance and ease of starting the engine, while also maintaining a consistent output across different speeds. This ensures a smoother ride and reliable performance. However, the installation process might be challenging for some users, especially those with limited mechanical experience, as it involves multiple components and precise assembly.

Additionally, while the durability and maintenance standards are good, being a 2-stroke engine, it might require more frequent maintenance compared to 4-stroke engines. Despite these considerations, the TTONSUE Bicycle Motor Kit offers a robust solution for bicycle enthusiasts looking to add a motor to their rides, provided they are comfortable with the installation process.

The CUBELLIN Upgraded 100cc Bicycle Engine Kit is designed to transform a regular 26"-28" bicycle into a motorized bike with a 2-stroke 100cc engine. It’s powered by gasoline and offers a top speed of around 48 km/h, making it a practical choice for those wanting to add extra speed without buying a full motorcycle. One of its standout features is its fuel efficiency—running about 150 miles per gallon, which helps keep running costs low.

Installation requires some mechanical skill, but the kit includes all necessary parts and a manual to guide through the process. The engine mounts use 8mm bolts instead of the common 6mm, providing stronger and safer attachment to the bike frame. The engine body is made of aluminum and iron components treated to resist wear, promising decent durability if maintained properly. However, as a 2-stroke motor, it will need regular maintenance like oil mixing and carburetor tuning for best performance. The kit comes with an upgraded carburetor that has adjustable settings, allowing better control over fuel delivery and easier starting in cold weather—an advantage for varied climates. It supports a maximum load of about 200kg (440 lbs), suitable for most adult riders with some cargo. This kit is especially good for users with limited budgets or those who want motorized assistance only occasionally or for short trips.

On the downside, the rigid suspension and absence of included brakes mean your existing bike setup must handle those safety aspects. Also, it may not fit all bike frames perfectly, so checking compatibility beforehand is important. While the speed and power are good for casual use, it’s not designed for heavy-duty or long-distance riding. This engine kit provides a cost-effective, fuel-efficient way to motorize a suitable bike with moderate speed and solid build quality, making it best suited for hobbyists or practical users looking for an easy upgrade rather than a full motorcycle replacement.