Best 4 Stroke Bicycle Engine Kit Reviews

Best 4 Stroke Bicycle Engine Kit Reviews | Top Picks in 2022

Best 4 Stroke Bicycle Engine Kit Reviews

The four-stroke motorized bike has no exhaust, offers quiet and easy operation. Though it is a power-assisted vehicle, it will give you the chance to use it as an actual bicycle as it retains pedals. To enjoy all the conveniences and ease of use, you should go for a whole kit. 

Since there are countless numbers of brands and packages, you may stumble choosing the right one for you. Fret not! I have narrowed down the five best 4 stroke bicycle engine kits. Without any further ado, scroll down to find out more to have the right one for you. 

Quick Summary of my top picked products:

1. 49cc BBR Tuning 5G Pull Start

This one has a 2-3 HP power motor with 20 to 25 mph speed, the gas tank is around 1.5L, Dimensions of the engine – 9″x 9.5″x 7″

2. BBR Tuning 38cc Lock-N-Load Friction

The Maximum speed is 15 MPH with a Maximum Torque of 5500r/min, Travel 100 miles with 100 gallons of fuel, Air-cooled

3. Flying Horse Complete 5G Transmission Kit

The power of the motor is 10.2 kw with 15 mph speed, a forced-air displacement cooling system to prevent overheating. 

4. 49cc Flying Horse 5G Engine Assembly

It contains Black 1.5L Fuel Tank with Fuel Valve and Fuel line, the kit can be used with 4-stroke engines of other brands also.

5. 4-Stroke Cycle Motor Kit Compete Gas Kit

The bike is compatible with 28” V frame bike and 26” ATV bike, Key Features, the maximum speed is around 32 MPH, this offers 2.1HP at 7,000 rpm.

How to Choose the Right 4 Stroke Bicycle Engine Kit for You?

Whenever you search for 4 stroke bicycle engine kits, you’ll find many options that are enough to make you puzzled. So, this buying guide will guide you through the important considerations you need to make before buying engine kits for your bicycle. 

Engine Size

Engines of different sizes are available in the market. An undersized motor won’t be able to control the load, while an oversized one will cause you extra costs for operations. So, picking up the right motor size is important. The right size varies based on the rider’s weight, terrain, top speed, and torque.  

Rider’s Weight 

Riders with less than 200 lbs. weight should purchase the smallest motor size. 48/50 cc motors will work fine for them. If you weigh more than 200 lbs., you should go for a 60 cc or bigger motor. Otherwise, the top speed will be an issue for you. 


You should also consider the type of terrain you will ride on. While flat terrain will be okay with a smaller motor, hilly terrains won’t. If you are going to ride in hilly areas, you will require a bigger motor because larger motors offer more torque which is helpful for hilly areas. The bigger the hills, the bigger the motor should be. 


There are sprockets with 36,40,44 or 48 teeth. Higher tooth sprockets provide higher torque and lower maximum speeds. Forty-four tooth sprockets offer an outstanding balance between torque and acceleration.

So, I recommend using this sprocket. However, it’s a good idea to buy customized sprockets. If you are happy to spend some extra bucks, we recommend purchasing a CNC sprocket. 

Kits Type

There are different kit types that you can choose depending on your riding areas and skills in installing the kits.  

1. Center Mount: Center mount engine kits are perfect for those who wish to ride around the neighborhood. You’ll need pretty decent mechanical skills and a lot of patience to install this type of kit. These kits are best for larger bikes. 

2. Rear Mount Chain Drive: Installing these kits is easier than the previous one. If you want serious transport rather than a hobbyist, a rear mount chain drive is the option. They require basic mechanical skills and patience, suit both men’s and women’s bikes. However, they can be noisy that makes them bad for use in the neighborhood.

3. Rear Mount Tire Roller: This one of the most accessible types of kits to install with less effort and time. Just follow the basic instructions that it comes with, and you should be able to install them. However, they are the nosiest type as well. 


4 stroke bicycle engine kits vary a lot when it comes to budget. Never buy the cheapest one to save your money. Consider buying from a reputed brand that offers a decent warranty. 80 cc and 66 cc engines are the same. So if you see an 80 cc engine with a higher price tag than a 66 cc engine, go with the 66 cc. 

How Did I Pick?

After going through the buying guide, you’ve probably guessed how I picked the products for you. I considered the engine quality at first. The weight limit and sprocket numbers were also my concern. The kits should bang for your bucks.

The payload capacity also varies from terrain to terrain. From beginners to professionals, all will be benefitted from the choices. I hope you find the right 4 stroke engine kit for your bike.

Just in case if you’re in a hurry….

Just check these two best kits from my review unit. You won’t regret it later.  

49cc BBR Tuning 5G Pull Start

49cc BBR Tuning 5G Pull Start
  • Twist grip throttle
  • Adjustable throttle cable
  • Runs silently
  • Easier to start

BBR Tuning 38cc Lock-N-Load Friction Drive

BBR Tuning 38cc Lock-N-Load Friction Drive
  • Compact design 
  • Fits with a wide range of bicycles 
  • Don’t need to install a rear-drive sprocket

5 Top-rated 4 stroke Bicycle Engine Kit: My Honest Review

Most of the riders nowadays are installing engine kits in their bicycles for better communication. Though four-stroke engine has less speed, the durability and less noise make them favorite to many. Let’s check out my recommended ones to find the right one for you!

1. 4 Stroke – 449cc BBR Tuning 5G Pull Start Bicycle Engine Kit

When looking for a bicycle engine kit that will offer the ultimate fuel efficiency with the smoothest ride, you should go for the BBR tuning 5G 4 stroke engine. With all the latest aspects and upgraded components, this one will speak of durability and longevity. 

Excellent Components

If we look at the components, it packs everything that you will need to get started. It includes a centrifugal transfer case, pull-start bicycle engine, low profile carburetor with high-performance features, hush muffler, chain tension guide and guard, engine mounting plate, and so on. 

This package comes with an instruction manual. However, this will not be going to help you while assembling the parts. 

Tips: You should install the engine mount first on the engine before installing it on the bicycle. Because if you install this mount onto the bicycle frame first, you won’t be able to get to the bolts that hold the engine to the motor mount.

Easy User-Interface

Thanks to its centrifugal clutch to minimize the manual engagement of the engine. 

This engine comes with around 2.5HP, which can hit a speed of a maximum of 35mph. With the pull start, you only need to pull the starter cord once or twice, and the bike will take off!

Great Built-Quality

Overall, the 49cc BBR Tuning 5G Pull Start 4Stroke Bicycle Engine Kit is exceptionally well-made in the market. You won’t experience any vibration while riding

Things We Like

  • Runs silently
  • Easier to start
  • Great value for the money.
  • It comes with great fuel efficiency 
  • You won’t experience any vibration 

Things We Don’t Like

  • The parts may seem heavier than the 2-stroke engine kits. 

2. BBR Tuning 38cc Lock-N-Load Friction Drive

Key Specs:

  • Engine Dimension: 8”x 10” x 9.5” 
  • Maximum Speed: 15 MPH 
  • Maximum Torque: 5500r/min
  • Mount: Over the wheel
  • Counter Clockwise PTO Shaft Rotation
  • Transistor Magneto ignition system
  • Fuel Capacity: Travel 100 miles with 100 gallons of fuel

If you want to go for smaller dimensions than our previous pick, you can choose this 38cc Lock-N-Load engine kit. It can turn your pushbike into a motorized bike.

Easy Installation

While looking for a no-fuss installation, this one is the way to go as there is no rear drive sprocket. This one mounts directly onto the wheel instead of in the center of the chassis.

Suitable for Flat-terrain

The engine comes with a maximum torque of 19.4mph on a 26” wheel and 23mph on the standard 26” wheels. The 38cc is enough for maintaining a standard pace on the hills.

That being said, the 38cc engine is more recommended for flat terrain.

Air-cooled System

I like its air-cooled system, which reduces overheating. Moreover, it has a built-in gas tank that eliminates the hassle of installing a separate gas tank.

However, it misses some of the parts in the same price range as the previous pick. On the whole, this package is nice and easy to install.

Things We Like

  • Compact design 
  • It goes with a wide range of bicycles 
  • Don’t need to install a rear-drive sprocket 
  • Easy to install

Things We Don’t Like

  • The speed is average
  • Some parts are missing 

3. 49cc Flying Horse 5G 4-Stroke Engine Assembly

Key Specs:

  • Power: 10.2 kW power 
  • Speed: 15 mph
  • Cooling system: Forced-air displacement cooling system
  • Components: Includes assembly motor, carburetor, and exhaust

When you don’t want to invest in a whole package, this kit is the way to go! This is a replacement of 4 stroke bicycle engine kit that contains the assembly motor, the carburetor, and the exhaust.

However, the package excludes transmission and some other essential components. So, it’s never been a complete engine kit. Purchase it only if you want to replace the listed parts.


Though the kit is from Flying Horse, you can use them with components from other brands. Moreover, the listed components are durable and of high quality. 

Great Power

The 49 cc 4-stroke engine provides 10.2 KW of power with which you can gain more than 15 mph speed. With this powerful engine, you can ride on hilly terrains also. The kits offer excellent fuel efficiency. The bike can travel about 100 miles per 100 gallons of fuel. 

Easy And Comfortable Ride

The pull start feature makes the engine faster to start and the ride less tiring. The stock exhaust muffler on the assembly makes the journey more comfortable. 

Things We Like

  • The kits are long-lasting
  • You can ride uphill with these kits
  • Forced air cooling system prevents overheating

Things We Don’t Like

  • TIt is not a full engine kit

4. Flying Horse Complete 5G 4-Stroke Bicycle Engine Transmission Kit

Key Specs:

  • Components: It includes everything needed for mounting the engine to your bicycle except the engine.
  • Capacity: It contains Black 1.5L Fuel Tank with Fuel Valve and Fuel line.
  • Compatibility: The kit can be used with four-stroke engines of other brands also.

This kit comes with everything you need to mount and run your 4-stroke engine onto your bicycle. If you have already purchased an engine and need the required accessories to mount it, this is the best option for you. 

Universal Fit

This transmission kit fits all the engines that are four strokes and have 3” bell rotor configuration. This includes the Grubee 4-stroke engine or almost all Huasheng 142F- 4-stroke engine kits. 

Easy Installation

Installing the engine with this kit is super easy. It has everything- a brand new transmission and 44 tooth sprockets, a sprocket clamp assembly, idler, a chain, the throttle grips, and other components that are needed for engine installation and smooth riding. 

Dual Chain Transmission

The heavy-duty dual chain is durable and is not prone to overheat, unlike the single chains or belt drive. It can be used for hours. 

Things We Like

  • The kits are durable
  • It fits a wide range of bicycles
  • The heavy-duty chain prevents overheating

Things We Don’t Like

  • The mounting plate is not up to the mark

5. 4-Stroke Cycle Motor Kit Compete Gas Kit

Key Specs:

  • Speed: 27-32 MPH
  • oil tank capacity: 2.5L
  • Compatibility: 28” V frame bike and 26” ATV bike 
  • power output: 2.1HP at 7,000 rpm
  • Torque: 2.7 NM at 4,500 rpm

While looking for a 49cc 4gstroke Bicycle Motor Kit complete package, our previous choices may seem pricey to some customers. Here is another option where you can save some of your bucks. The Iglobalbuy 49cc 4-engine kit comes at an economical price. 

Great Combination 

With 44 sprockets and 32mph speed, this one is the most incredible, affordable product. You can also find the high-performance 2-stroke engine parts, but the four stroke kit offers quiet and low vibration operation. 

With the recoil starter, forced splash lubrication system, and transistorized magneto ignition, you can expect no-fuss handling of your motorized bike. 

Suitable for V-shaped Chassis 

Thanks to the manufacturers for giving some specific frame requirements, as you don’t have to get confused now. This kit goes with V-shaped frames. 

Awesome engine

The motor is undoubtedly quite efficient. With wide crank pedals, you will enjoy the most out of it. This kit is suitable for small rides, but you can modify it by various customizations. 

Things We Like

  • Robust build
  • Easy to install.
  • Great value for the money
  • Easy to follow instructions

Things We Don’t Like

  • You need to do some modifications to the parts

Frequently Asked Questions

1. How long will the 4 stroke engine last?

The engines will generally last 3-10 years with a total mileage of 5000-7000. 

2. What is the top speed of 49cc motorized bicycle?

The maximum speed is usually around 25 mph.

Yes, a bicycle with a motor is legal. To ride this vehicle on the road, you need to have proper equipment and license.

What is Motorized Bicycale?


Have you got the best 4 stroke bicycle engine kit for you? I am pretty sure that you will face a lot of questions while making your first purchase. Once you have gone through the buying guide, you will get a clear idea about the ins and outs of your kit. The kit will turn your standard bike into a motorized bicycle for an easier commute. 

Additionally, with the 4 stroke engines, you don’t have to mix gas and oil. These also produce more torque as the motors are controlled by valves that regulate the fuel flow. Let me know in the comment section which one is your favorite between 2 stroke engine vs. 4 stroke engine