Adding a gas motor to a bicycle can transform your commute or off-road adventures, but choosing the right kit requires careful research. We compared manufacturer specifications, industry safety guidelines, and aggregated owner feedback across dozens of models to identify the top performers. Our evaluation focuses on power, reliability, ease of installation, and safety compliance. Below are our researched picks, each with honest limitations and who should consider an alternative.
| Photo | Product | Score | Buy |
|---|---|---|---|
 |
Bicycle-Engine-Kit 80cc 2-Stroke Best Overall 80cc, 2-stroke, single-cylinder, air-cooled, 2.5-3 HP |
9.0 | 🛒 Check Price |
 |
BikeBerry 66cc 2-Stroke Motorized Bicycle Engine Kit Best Value 66cc, 2-stroke, single-cylinder, air-cooled, 2 HP |
8.7 | 🛒 Check Price |
 |
Zeda 80 80cc 2-Stroke Firestorm Bicycle Engine Kit Best Performance 80cc, 2-stroke, single-cylinder, air-cooled, 3.5 HP with performance exhaust |
9.2 | 🛒 Check Price |
|
Grubee Skyhawk 66cc 2-Stroke Bicycle Engine Kit Most Reliable 66cc, 2-stroke, single-cylinder, air-cooled, 2 HP, cast iron cylinder |
8.4 | 🛒 Check Price |
 |
Bicycle-Engine-Kit 50cc 4-Stroke Best 4-Stroke 50cc, 4-stroke, single-cylinder, air-cooled, 1.5 HP |
8.1 | 🛒 Check Price |
 |
BikeBerry 80cc 2-Stroke Motorized Bicycle Engine Kit Best for Beginners 80cc, 2-stroke, single-cylinder, air-cooled, 2.5 HP |
7.8 | 🛒 Check Price |
 |
Bicycle-Engine-Kit 79cc 4-Stroke Most Powerful 4-Stroke 79cc, 4-stroke, single-cylinder, air-cooled, 2.5 HP |
8.3 | 🛒 Check Price |
1. Bicycle-Engine-Kit 80cc 2-Stroke: Best Overall
The Bicycle-Engine-Kit 80cc 2-stroke is our top pick for its balance of power, reliability, and value. Based on owner feedback and the spec sheets, this kit delivers consistent 2.5-3 HP, enough for speeds up to 30 mph on flat ground. The CNC-machined components and reinforced mounting bracket improve durability and reduce vibration compared to budget alternatives. However, the 2-stroke engine requires fuel-oil mixing, which can be messy for some users.
Who should skip this: If you prefer the convenience of separate oil and gas (4-stroke) or need a quieter ride, consider a 4-stroke kit. Also, this kit is not ideal for complete beginners due to some tuning required out of the box.
- CNC-machined cylinder head and intake manifold for improved airflow
- Includes all mounting hardware, sprocket, chain, and throttle assembly
- Reinforced mounting bracket reduces vibration and frame stress
Pros: Strong power-to-weight ratio for hills and acceleration; Comprehensive kit with clear instructions
Cons: 2-stroke requires pre-mixing oil and gas
2. BikeBerry 66cc 2-Stroke Motorized Bicycle Engine Kit: Best Value
The BikeBerry 66cc kit offers excellent value for budget-conscious builders. Our research and owner feedback indicate it delivers reliable 2 HP with minimal modifications. The pre-assembled engine and upgraded ignition components reduce initial setup hassle. However, the 66cc displacement is less powerful than 80cc options, so expect lower top speed and hill-climbing ability.
Who should skip this: Riders in hilly areas or those over 180 lbs may want a larger displacement kit. Also, if you want a turnkey solution, this kit still requires some mechanical assembly.
- Pre-assembled engine with upgraded CDI and spark plug
- Includes heavy-duty sprocket adapter and tensioner
- Compatible with most standard and cruiser bicycle frames
Pros: Affordable entry point with reliable performance; Good customer support and online resources
Cons: Lower displacement may struggle on steep hills
3. Zeda 80 80cc 2-Stroke Firestorm Bicycle Engine Kit: Best Performance
The Zeda 80 Firestorm is the performance leader in our evaluation. Manufacturer specs and owner reports confirm 3.5 HP output with the included expansion chamber, making it ideal for riders who want maximum speed. The high-compression head and upgraded carburetor provide crisp throttle response. However, this kit costs more and may require fine-tuning to reach peak performance.
Who should skip this: Casual riders or those on a tight budget will find better value in the BikeBerry or Bicycle-Engine-Kit. Also, the added power may overwhelm a bicycle frame not designed for motorization.
- High-compression cylinder head and performance expansion chamber
- Upgraded NT carburetor and high-flow air filter
- CNC billet intake manifold and heavy-duty clutch pads
Pros: Exceptional power for speed and hill climbing; Quality components reduce vibration and improve longevity
Cons: More expensive than standard kits
4. Grubee Skyhawk 66cc 2-Stroke Bicycle Engine Kit: Most Reliable
The Grubee Skyhawk is a benchmark for reliability. Based on aggregated owner feedback, its cast iron cylinder and balanced crank provide exceptional longevity, often outlasting other kits by thousands of miles. The kit is well-engineered with quality gaskets and hardware. However, the cast iron adds weight, and the 66cc displacement limits top-end power.
Who should skip this: Riders prioritizing lightweight builds or maximum speed should look at the Zeda 80. Also, the higher price for a 66cc kit may not appeal to budget shoppers.
- Cast iron cylinder liner for extended engine life
- Double-bearing crank and balanced crankshaft reduce vibration
- Includes upgraded spark plug and wire
Pros: Renowned for durability and long service life; Smooth operation with less vibration
Cons: Heavier than aluminum cylinder kits
5. Bicycle-Engine-Kit 50cc 4-Stroke: Best 4-Stroke
The Bicycle-Engine-Kit 50cc 4-stroke is our pick for those who prefer simplicity and cleanliness. Owner feedback highlights the convenience of separate oil and gas, and the automatic clutch makes starting straightforward. However, the 50cc displacement delivers only 1.5 HP, which is adequate for flat terrain but inadequate for steep hills or riders over 150 lbs.
Who should skip this: If you need to climb hills or want higher speeds, a 2-stroke 80cc kit is a better choice. Also, the 4-stroke is heavier and may require frame modifications for fit.
- Separate oil and gas (no mixing required)
- Quieter operation and cleaner exhaust than 2-stroke
- Automatic centrifugal clutch for easy starts
Pros: Easy to maintain and fuel; Lower noise and emissions
Cons: Less power; struggles on hills and with heavier riders
6. BikeBerry 80cc 2-Stroke Motorized Bicycle Engine Kit: Best for Beginners
The BikeBerry 80cc kit is tailored for beginners, with video guides and included tools. Our evaluation found the kit provides adequate 2.5 HP for most riding, and the pre-assembled engine reduces initial complexity. However, owner reports indicate that the stock spark plug and carburetor may need replacement for optimal performance, adding cost and effort.
Who should skip this: Experienced builders looking for high-quality components may prefer the Zeda 80. Also, if you want a truly plug-and-play experience, consider a 4-stroke kit.
- Step-by-step video instructions included
- Pre-assembled engine with basic tuning
- Includes all tools needed for installation
Pros: Good instructional support for first-time builders; Decent power for the price
Cons: Some components may require immediate upgrades (e.g., spark plug)
7. Bicycle-Engine-Kit 79cc 4-Stroke: Most Powerful 4-Stroke
The Bicycle-Engine-Kit 79cc 4-stroke offers the best power among 4-stroke options, with 2.5 HP from a 79cc engine. Our research shows it competes with 80cc 2-strokes in speed while offering the convenience of separate oil and gas. However, its weight and size can make installation challenging on standard bicycle frames, and the centrifugal clutch may slip under heavy load.
Who should skip this: Riders with smaller frames or those who prioritize lightweight builds should consider a 2-stroke kit. Also, the higher cost may not justify the marginal power gain over 50cc 4-strokes for flat-terrain use.
- Large displacement for a 4-stroke, comparable to 2-stroke power
- Separate oil and gas system
- Heavy-duty mounting plate and chain tensioner
Pros: Strong power without mixing fuel; Quieter than 2-stroke alternatives
Cons: Heavy and bulky; may require frame modification
Frequently Asked Questions
Is it legal to ride a gas-powered bicycle on public roads?
Laws vary by location. In many areas, gas bicycles are classified as mopeds and require registration, insurance, and a driver’s license. Some states limit engine displacement (e.g., 50cc) and speed. Always check your local traffic laws before purchasing a kit.
What tools and skills are needed to install a gas motor on a bicycle?
Basic mechanical skills and tools like wrenches, screwdrivers, and a drill are typically required. Most kits come with instructions, but some may need minor frame modifications. If you are not comfortable with engine tuning, consider a 4-stroke kit with an automatic clutch.
How fast can a gas-powered bicycle go?
Speed depends on engine displacement, gearing, rider weight, and terrain. A typical 80cc 2-stroke kit can reach 25-35 mph on flat ground. Larger or tuned engines may exceed 40 mph, but safety and legal limits apply.
What is the fuel economy of a gas bicycle motor?
Most 2-stroke kits consume about 1 gallon of fuel per 100-150 miles, while 4-strokes are slightly more efficient. Actual mileage varies with riding style and maintenance. Pre-mixing oil for 2-strokes adds to the cost.
Can I use a gas motor kit on any bicycle?
Most kits fit standard diamond-frame bicycles, cruisers, and mountain bikes with a bottom bracket clearance. Bikes with suspension, disc brakes, or unusual frame geometry may require modifications. Always check the kit’s compatibility with your bike’s frame and wheel size.
Our Verdict
After researching specifications, safety standards, and owner feedback, our top pick is the Bicycle-Engine-Kit 80cc 2-Stroke for its overall balance of power, reliability, and value. For those who prioritize performance, the Zeda 80 Firestorm is the runner-up, offering the highest power output but at a higher cost and complexity.
