How to Put a Lawnmower Engine on a Bicycle


Everyone knows how steeper it becomes to climb up a hill as you grow older. But if you install a little engine with your bicycle, you will easily overcome the hills.

I am not telling you to buy a new motorcycle for this task. Instead, you can do the job with your old bicycle by adding a petrol power motor with it. In fact, a lawnmower engine can do the work. But do you know how to put a lawnmower engine on a bicycle? Don’t worry; I will show you how in this article.

How to Put a Lawnmower Engine on a Bicycle

Summary: Instructions for putting a lawnmower engine on a bicycle:

1. Obtain a bicycle with a lawnmower engine already installed.

2. Remove the engine from the bicycle.

3. Disassemble the engine.

4. Locate and remove the bolts that secure the engine to the bicycle frame.

5. Place the engine pieces on the bicycle frame.

6. Reinstall the bolts.

7. Test the engine by starting it.

Required Materials:

  1. Bicycle frame that can accommodate wheels and a drive train.
  2. Engine with transmissions, such as from an old lawnmower or chainsaw.
  3. Chain for the drivetrain.
  4. Hand grips on either side of the handlebars to hold onto while riding.
  5. Seat attachment.

Processes on How To Put A Lawnmower Engine On A Bicycle

Process One:

Step One: Acquire Lawnmower Engine

If you’re looking for a great deal on a used car, your local flea market or Craigslist are great places to start your search. You can usually find cars for as little as $100, and since you’ll likely need to buy other items like car insurance and a parking permit, it’s easier to find everything you need in one place.

Step Two: Scope Out The Bike

Keep in mind what type of bike it will be put onto when looking for an engine and the size of the front wheel hub diameter. For example, if I were putting my lawnmower engine on this bicycle, I would want one with a 20-inch front wheel and a large enough exhaust pipe to hit against the frame.

Step Three: Take Apart  Bike

I recommend taking the bike down to its frame so you can measure and ensure everything will line up right before mounting anything on it.

Step Four: Make A Plate For the Exhaust Pipe To Pass-Through

This is needed because a lawnmower engine has an exhaust pipe larger in diameter than most bicycle front wheels. This means they won’t fit side by side as designed and rub against each other when turning corners or at high speeds, which could cause serious damage like blowing out your tire.Exhaust Pipe To Pass-Through

If the pipe hits your wheel while riding, then be prepared for one of two things: wrapping tape around the exhaust pipe to act as a shield or just replacing your front wheel with one that will fit.

Step Five:

Mount the transmission and cut off pegs, final touches, and test ride!

Process Two

For this project, I took out the engine of my lawnmower and installed it inside the rear triangle part of my bicycle. The engine will require quite a big place, and as it will be the main power source, I have removed the center sprocket for the installation.

My bike is small, so I had to remove the bottom rod from it too. Next, I set the engine in the center and determined the exact distance measurement. I have created a CAD model based on the measurement and then cut out a steel mounting bracket according to that model.

After mounting the engine and its parts, I removed the old sprocket and used shims for the new sprocket. Then I made a jackshaft with my design and cut out some slots for tightening the chains. Next, I made the center rod, which is quite necessary for holding my weight.

Removed Old Sprocket

So, I cut that out and bent it slightly to match the frame. To finish up the process, I put the chains and then belts. That’s it; the process is completed.


  • Wear safety goggles when working on your engine.
  • Keep kids and pets away from the area where you work with heavy equipment.
  • Always wear a protective face mask to avoid inhaling any chemicals that may be in use during the process or as an emergency measure if something goes wrong (like gasoline fumes). If possible, work outdoors so bystanders can quickly clear out of range should anything happen.

Frequently Asked Questions

What Kind of Motor Can I Put on a Bicycle?

Three types of motors can be put on a bicycle: hub motors, chain drive motors, and derailleur motors.

Hub motors are the most common type of motor, and they work by turning the wheel with a motor attached to it. This type of motor is usually used in small electric bikes because they don’t require a lot of power.

Chain drive motors are similar to hub motors but use chains to turn the wheel. They are usually used in larger electric bikes because they provide more power and are easier to operate.

Use a Larger Electric Bikes

Derailleur motors are rarer than the other two types of motors but are also the most powerful. They work by using gears to change the wheel’s speed and can be found on high-end electric bikes.

Can You Put a Motor on a Bicycle With Gears?

No, you cannot put a motor on a bicycle with gears. Gears are designed to allow the bicycle to move in one direction while the motor helps you move in another direction.

What Can I Use My Lawnmower Engine for?

You can use your lawnmower engine to power various tools, including a chainsaw, snow blower, or vacuum cleaner. You will need to install an engine conversion kit to power these tools. This kit includes everything you need to connect the lawnmower engine to the tool, including a belt, pulley, and clutch.

Once you have installed the engine conversion kit, you can start using your lawnmower engine to power your favorite tools.

Can I Put a Motor on My Bicycle?

Yes, you can put a motor on your bicycle. However, it is important to be aware of the laws in your area related to bicycles and motors. You should also consult an experienced bike mechanic to ensure the installation is done correctly and without any problems.

You Can Put a Motor  On Your Bicycle

Final Thoughts:

In this article, we’ve seen how to put a lawnmower engine on a bicycle. It’s not difficult and is actually pretty straightforward with the right tools. The most important part of putting in an engine is ensuring that you have enough clearance for the valves because they will determine whether or not it runs well!

It would help if you made sure that your front wheel hub has at least five inches from where the crankshaft meets the tire’s rim until it connects to the frame. You’ll also want around two inches between your valve covers and other parts like brake pads or levers, so adjust accordingly when installing everything.

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Jennifer Branett
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