Self-Made Mechanic 101 – How To Put A Motor On A Bike Step By Step

By Conrad Kühn

Ever realize how steep the slopes get as you grow older? And how you wish you had a little boost every time you come across a hill? Maybe it’s time to motorize your bike with our guide on how to put a motor on a bike step by step.

Gas power added to the leg power is equivalent to a new realm in biking.

Now, before all the fitness fanatics light up their torches and sharpen their pitchforks to come and get us, we will be the first to acknowledge the health rewards of a vigorous cycling session.

Yet, a good setup of the engine still lets you put your foot on the pedal and burn the road — and those calories.

You might not be on top of your cycling performance because of a physical disability. Load a motor on your rear wheel and take the long, scenic home route and glide past the boys in spandex.

Tools Required

• Bike motor set (Read the FAQ section to find out what types of Bike engines are available)
• Measuring cups and containers for petrol or oil
• Spray lubricant
• Zip ties
• Starter fluid
• Tools: pliers, screwdrivers, wrench

Steps To Follow

STEP 1: Bike and Motor Compatibility

Take into account the kind of motor you wish to install to the frame of the bike. Check whether the engine of your choice fits the triangular area you on your bike. The motor needs ample breathing space, so if it’s congested and doesn’t fit then you can’t install the motor and you might have to pick a smaller motor or change your bike frame.

The bike also has to be quite sturdy.

STEP 2: Install the sprocket

People usually have the habit of using the same sprocket when customizing a bicycle, which isn’t recommended. The justification not to use the bike ‘s old sprocket is because of the low torque it will deliver.

If you mount a new sprocket, however, you can relax knowing that it is sturdy and well-matched with the other components you received with the kit. 

Use a spanner to release the two nuts of the rear wheel. Then remove the chain linked to the sprocket of the rear wheel and slowly take off the back wheel.

Insert the rubber bush onto the shaft of the tire on either side. Insert the sprocket screws inside. Install a steel washer behind the screws for easy screw removal.

Tighten all the nut screws and replace the rear wheel

STEP 3: Fit the Motor

This step is quite simple.

Start by taking the motor out of the kit and place it on the triangular area of the frame. With the help of a nut, fit it on to the bike using the mounting bracket.

STEP 4: Install the Spark Plug

The spark plug is used to create the petrol spark. Attach the spark plug to the top of a motor by rotating it.

If a spark plug isn’t properly placed, your bicycle won’t fire.

STEP 5: Install the Clutch

The clutch resembles a handbrake. We mount this clutch for engaging and disengaging the engine usually closer to the left handle.

Replace the left brake lever with the clutch. Insert the other end of the wire into the hollow bar in the motor. Now tighten the wire using the threaded screw. Repeated use of the clutch will loosen the screw so make sure to tighten it frequently.

Hold the clutch to see if that long bar also moves inside. After releasing the clutch, it will come to its straight postilion.

Bicycle Circuit

STEP 6: Fit the Chain

The chain goes in between the bike sprocket and the engine shaft sprocket. 

Open the motor cover where the sprocket is located. Expose the chain completely by removing the master link.

Take one end and fit it inside the engine sprocket. After inserting a few chain links turn the engine gear using a ratchet.

The other of the chain goes over the sprocket in the rear wheel and then link the chains by connecting the master link. If the chain has slack, then remove some chain links.

Consider using a chain tensioner if you can’t get the right amount of tension

STEP 7: Set the throttle up

Insert the accelerator on the right side of the handlebar and connect it to the carburetor.

STEP 8: Install the Carburetor

Insert the carburetor into the engine manifold.

STEP 9: Mount the Petrol Tank

Using the mount bracket, fit the petrol tank onto the straight bar of the bicycle.

Then, connect the manifold of the tank to the carburetor using the tube provided in the kit.

STEP 10: Install the muffler A.K.A silencer

Attach the silencer to the engine exhaust using bolts provided.

And there you have it! You now have a DIY motorized bike.


When purchasing a bicycle motor kit, there are a few unique aspects to consider. You need to be skilled with a set of tools, and also need to know how a bicycle motor works.

It will be a misuse of precious time and cash if you install a bicycle engine incorrectly. It can also be quite dangerous.

Further Down is a guide on a few pointers to consider when looking for the best bike kit and the reason why you should maybe buy a motor kit. We also discuss the kind of bike kits and specify why certain model may require a specific type of license to ride.

Are You Sure I don’t Need a Mechanic?

If you’re a natural with a set of tools and can easily follow the directions, then it shouldn’t be an issue to build a motorized bike.

However, it’s not for everyone as the procedure usually takes at least a few hours, even for the most skilled DIY specialist with electronic abilities. Analyze the kit you’re planning on buying before you purchase it and make sure you check out a few reviews from people that used the kit firsthand.

What’s the Legal Status of a Motorized Bike?

The answer to this question is not clear because many different factors determine whether or not a motorized bike is legal.

Factors include the power source such as gas or electricity and the size of the motor. The laws can be different from location to location so therefore it also depends on your local authority.

In Washington, a bike with either 2 or 3 wheels powered by up to 1000W electric motor with a maximum speed of 20mph is classified as an electric-assisted bike. If your bike falls under this categorization then you are allowed to ride your electric bike in places where a regular bike is allowed except for sidewalks.

If your engine is powered by petrol, the laws will change, and another statute will apply.

Your bike can fall into two categories. It can be either labeled a moped or motor-driven bike. An engine less than 50cc, with horsepower less than 2 and a 30 miles per hour maximum speed will fall into the first category. Motor-driven bike, if the horsepower is less than 5.

You will have to obtain a permit, a driver’s license, and an identification number for the vehicle. These regulations and restrictions vary depending on the location, make sure always check your local laws before making a purchase.

red motor bike

What Type of Motor Should I Pick?

This question has several deciding factors:

– How often and where will you use the bicycle?
If you plan on occasionally use the motorized bicycle, then you don’t need to get a motor with the biggest fuel size. Where are you going to use the bike? What kind of surface? Are you going to be climbing many slopes? What about your weight? Before buying a motorized bike conversion set all these considerations should be addressed.

– Your budget?
Bike conversion kits differ considerably in price, but we will never suggest purchasing the kit at the lowest price.

Always buy from a highly regarded brand offering a reasonable warranty, in case something goes wrong.

– 2 stoke or 4 stroke?
A version of the internal combustion motor which has a cycle of two stokes moving up and down each is called a 2-stroke engine. When the cycle moves up and down 4 times each it is called a 4 stroke engine. 

Bike motors have either two or four strokes.

Torque produced by a 2-stroke engine is usually higher as they use a mixture of gas/oil, but the noise and environmental pollution are high. By contrast, a four-stroke engine provides an effortless and less exhausting ride. They just take gas in the tank, too.

– Different types of kits
There are different bicycle engine kits available to buy and before you make the move and purchase one, do your research. Deciding on the appropriate type of bike kit depends on a variety of criteria including your mass, landscape, torque, and max speed.

Riders with lower weights can select the smallest size of the motor-48/50cc and it’s usually a perfect fit. When you weigh more than 200 lbs (90kg), then a bigger motor would be best suited to your needs. Hills require larger motors, so bear in mind the terrain you’ll be riding in.

1. Center Mount Motor
This type of kit is a perfect fit for riders who plan on using their bike around the local town. If you’re an enthusiast, that’s the right engine kit type for you. Installation of a center mount kit isn’t that difficult but will take some considerable amount of time. You’ll also need to know your way around tools. 

The center mount requires a lot of space and works best with bikes that have a big frame.

2. Chain Driven Rear Motor
The rear mount drive is the most popular kind of kit out there. It is reliable, durable, and can be used for a long time without any problems. These kinds of kits demand simple mechanical expertise but will take quite some time to mount. However, you won’t be disappointed by the end result.

These kits can be attached to a wide variety of bicycles with different kinds of frames that are made to accommodate men or women. 

Noise pollution might be an issue if you live in the suburbs.

3. Rear Mount Tire Roller
The easiest type to install is the rear mount tire roller. With accurate guided instructions and a few common mechanical tools, this type of kit shouldn’t take too long to install.

Just like everything, it has its pros and cons. The rear mount motor will give you the smoothest experience but the noise pollution levels will be over the top.

– What about electric conversion kits?
Electric conversion kits are quite similar but involve different steps. You can read our guide on how to convert your bike into an electric bike.

Finally, remember that seeking expert assistance is never a bad idea.

If this guide worked for you or if you just simply like reading it, make sure to share it on Facebook!


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