Gas Powered Bycicle




About: Travelling since 2013. I'm currently in Australia for some reason. --- I’m Calvin Drews, and I love to learn, experiment, invent, create, repair, and generally just do things myself. A sort of modern jack o...

 This is a bike that my brother and I installed a 47cc engine on. The engine is from ThatsDax, and I recommend them to you if you want to do something like this. The installation of the hardware took about 2 days, bug fixing and fine tuning took another 2 days.

TIP: The mysterious problem we encountered was the engine refusing to start. This is solved by tightening the star nut inside the clutch (before, the clutch would slip). Now it works like a charm and starts up almost every try!
Also, make sure nothing rubber/plastic is touching the engine. It gets very hot :)

My top speed is 25-27 MPH. I could go faster, but it's a new engine and I don't want it to overheat.

My fuel is 1/2 gallon gasolene mixed with about 3.5 ounces of 2 stroke engine oil.

This is just a video of how the engine runs, I'm not sure how to film it in action yet.

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26 Discussions


2 years ago

i love your instructables


4 years ago

Can I put a smaller sprocket on my bike rim when I put this 80cc motor on my bike?


5 years ago

I have one and I got pulled over by a cop. It turns out that you need a drivers license to ride one in the streets in NY.


Reply 9 years ago on Introduction

No welding, I wish I had a welder though XD The engine is from a website called ThatsDax. ThatsDax was the vendor I chose because they are in the USA and had the lowest prices...if you are located in the USA, I strongly recommend you buy the engine from them, because you can call Duane if you need any help, and it won't take months to ship to you. If you do buy your engine off e-bay, it's going to come from Hong Kong and take months to ship.


Reply 7 years ago on Introduction

Not always, but there are bugs with them... I bought one on Ebay and it arived within three weeks... The engine's currently down for electrical repair though...


Reply 8 years ago on Introduction

Below is an excerpt from a California government website. These are pretty much the same laws in Michigan (where I live)...and, from what I read, they are rarely enforced. Build your bike, ride smart, and don't make a big deal. No cop is going to pull you over if you don't cause any trouble.


Q: What is a “motorized bicycle” and what are the rules and requirements to drive them?

A: First, there are two types of motorized bicycles. The first is a moped or motorized bicycle – a two-or-three-wheeled device having fully operative pedals for propulsion by human power, or having no pedals if powered solely by electrical energy, has an automatic transmission, a motor which produces less than 2 gross horsepower, and has a maximum speed of not more than 30 miles per hour. The second is a device that has fully operative pedals for propulsion by human power and has an electric motor that has an output of not more than 1,000 watts, and has a maximum speed of not more than 20 miles per hour. Motorized bicycles do not need to be registered. However, you will need a Class M1 or M2 (moped only) license to drive and helmets must be worn by all riders.

Q: Are motorized bicycles or mopeds allowed on city streets?

A: Motorized bicycles are allowed on bicycle lanes that are adjacent to a roadway. They may be ridden on the street on the far right hand side as to not impede traffic if a bicycle lane is not available. Motorized bicycles are not allowed on bike paths or lanes that are not adjacent to the roadway or any other pedestrian trail or path unless otherwise posted. Do you have questions about general driving related requirements like registration and insurance? Are you unclear about laws and restrictions related to driving? Readers can submit any DMV-related questions to"


Reply 9 years ago on Introduction

In most states, as long as the engine 49cc or less it's completely legal and requires no special license FOR THE BIKE. The rider may still have to have a DL. In Arkansas, use of "any" motorized vehicle (including electric) on public roads requires the driver/rider to be licensed.


Reply 9 years ago on Introduction

legal?- sort of :D
I live in Michigan, and there are no laws that pertain to this sort of thing (not a moped or a bike). Besides, no one really cares as long as I don't hold up traffic or rid 25mph on the sidewalk ;)


Reply 9 years ago on Introduction

I've touched the engine a few times, and it's not searing hot. I've never been burned :)