ZB 66cc/80cc Bicycle Engine Kit

  • Sale
  • $149.95
  • Regular price $249.95



The strongest bicycle racing engine out there. This 2 stroke bicycle engine kit features a 45 degree angled spark plug and include a steel intake manifold, with a larger inner diameter for improved performance. This engine has a 1 3/8 (1.375) inch diameter down-tube engine mount accommodating the most common bicycle frames. Higher grade nuts and bolts are used throughout the entire engine.

Improved fuel line quality is included with these kits that don't get hard over time.

Strong gas tank clamps are now packaged which help create a secure bracket mount for the gas tank to the frame of the bicycle. The gas tank mounting bolts measure 1 1/8 (1.125) inches long and a spring loaded gas tank cap is included.

Stronger and more durable idler wheels, and a quieter and more fluid roller system.

The hemispherical (half-circle) end-cap and larger exhaust pipe diameter make for a smoother-running, more powerful engine. These mufflers are heat shielded to prevent your leg from coming in contact with the muffler. A clamp for holding the Exhaust Muffler to the frame of the bike is included with this package.

The large frame tube adapter accommodates up to 2 inch diameter down tubes.

This complete 66cc/80cc bicycle engine kit package comes with every thing that you'll need to put together and build your own racing engine, and proceed to convert any regular 26" single speed or multi speed mountain bike into a motorized bike. You'll still be able to pedal the bike and ride like normal or start the engine by releasing the clutch lever. There's no rope pulling needed. You can stop or start the engine as you ride. Twist grip hand throttle controls speeds from 38 to 53 km/h depending on the gear ratio. This installation kit comes with a 44 tooth 9 hole sprocket with easy to install 9 bolt universal mounting hardware that clamps over the rear wheel hub and spokes. This creates a totally independent drive sprocket and chain that does not interfere with your current drive chain or peddling.

With the built in clutch you maintain full function of the original bike. Pedal, shift, and ride your bike like normal. The engine kit only adds about 20 lbs to your bike. When you want to engage the engine simply release the clutch hand lever and the engine springs to life. To power off, simply press the included kill switch.


What do I need to put my motorized bike together?
1. Requires basic mechanics and simple tools (any mechanical experience always helps!) There are a number of Youtube videos and references we offer to help with installation.
2. It takes about a few hours to install while using easy to follow detailed instructions (which can be found on our website at https://zoombicycles.com/pages/installation-help  or by copying and pasting that URL link into your browser. If you are unable to download or access the site, please send us an inquiry and we will be happy to send you the details directly.


What type of bicycles with these racing engines fit on?
The 66cc/80cc bicycle engine kit requires a clearance of at least 15 inches in height on the seat tube (the part of the frame under the seat) and 14-15 inches in length on the down tube (the diagonal part of the frame), and it is approximately 5 inches wide. 

We recommend installing these kits on bicycles with a 1 inch diameter seat tube and with a 1-1.25 inch diameter on the down tube.
We have a gallery available on our website and you'll be able to view a selection of bicycles that these engines have been installed on.


Model: ZB-80CC-SLVR
*Please note that all engine assembly parts are provided and will require 10-15 minutes to assemble the components of the engine. Some mechanical aptitude is recommended.
Engine type:
Single cylinder, air-cooled, 2-stroke
Power * Rotary Speed
Rated Power:
2.5Kw / 5000r / min
Max Power:
3.5Kw / 6000r / min
Ignition Mode: CDI
Fuel type: 
Octane 89 and above
Lubrication Oil: 
2 Stroke Synthetic Motorcycle Oil
Mixing Ration for Fuel and Oil: 16:1 for new engines (20:1 after running approx 500Km)
Spark Plug: 4118C
Fuel Consumption: 2.5L / 100Km
Clutch Type: Friction Plate / Dry
Max Speed: 50 km/h

Designed to fit most 26” Bicycles (Cruiser, Road, Mountain, Chopper) with a Standard V-frame. Approximately 9-11” of clearance is necessary between the top bar and bottom bracket with a frame diameter of around 1”.

What's included:

Box A

  • 1 x Box of 80cc Class (66cc True Displacement) ZB-JET80-SR Complete Top End Assembly
  • 1 x Push Clutch Lever
  • 1 x Heavy Duty 415 Chain
  • 1 x Chain Guard
  • 1 x Throttle Cable (Adjustable)
  • 1 x Exhaust Muffler (Heat shielded and racing tuned)
  • 1 x Exhaust Muffler Support Clamp
  • 1 x Adjustable Bearing Chain Tensioner
  • 1 x Dished 44 Tooth sprocket with 9 oblong holes
  • 1 x NT Speed Carburetor 

Box B

  • 1 x 80cc Class ZB-JET80-SR Complete Bottom End Assembly
  • 1 x Box of Mounting Hardware and accessories (includes the following)
    • 9 x Sets of Mounting Bolts, Washers and Nylock Locking Nuts for the Sprocket Assembly
    • 2 x Rubber Sprocket Mounts
    • 3 x Semi-circle Metal Sprocket Mounts
    • 4 x Nylock Gas Tank Mounting Nuts
    • 1 x Inline Soft Plastic Fuel Filter
    • 1 x Gas Fuel Valve with Nylon Fuel Filter and Fibre Washer
    • 1 x Chain Guard Fasteners
    • 2 x Fuel Tank Fasteners
    • 1 x Large Frame Tube Adapter mounting plate with U Bolt and Engine Adapter Bolts.

Box C

  • 1 x 2L Glossy Black Finish Gas Tank
  • 1 x Spring Loaded Gas Tank Cap
  • 1 x High Quality Fuel Grade Line
  • 1 x Throttle Assembly with built in Kill Switch and Matching Grip
  • 1 x CDI (Capacitor Discharge Ignition) Module with mounting assembly
  • 1 x ZB-JET80-SR Top End Assembly Pack (includes the following)
    • 1 x Aluminum Head Gasket
    • 1 x Cylinder Base Gasket
    • 1 x Spark Plug
    • 1 x Japanese Needle Bearing Cage
    • 1 x Wrist Pin
    • 4 x Lock Washer Set

User Manual (now accessible only through https://zoombicycles.com/pages/installation-help)

  • Includes all the specifications, performance ratings and parameters.
  • Outlines Spark plug and clutch adjustment procedures.
  • Troubleshooting tips.
  • Basic installation of rear sprocket and engine instructions. More detailed instructions are also available (which can be accessed on our website at https://zoombicycles.com/pages/installation-help)
  • Parts breakdown and diagram of engine breakdown.


- Operating this motorized bicycle or bicycle engine kit involves some risk of serious bodily injury . Buyer accepts responsibility for any and all vehicle operation that may lead to personal injury, economic loss, social distress, other losses, costs and damages.
- Seller is not responsible for injuries and/or damages resulting from operating or use of any motorized racing bicycle engine parts or accessories.
- Not all motorized bicycles are permitted for road use. Check with your local Vehicle Insurance services for requirements. We do not offer any guarantee for legal road use.
-All of the ZoomBicycles gasoline operated products are NOT compliant with Environmental Protection Agency ( E.P.A. ) or California Air Resources Board (C.A.R.B) for the use on/off Public roads. Upon purchase, the purchaser agrees to use products for racing (closed-course competition) only and NOT for on/off public roads.


Important Note:
Over the years our manufacturers have advertised their largest sized engines as 80cc engines and therefore is listed in the same manner on our site. However based on the results provided at the time of Displacement Testing and Certification, these engines have been recorded with a true displacement of 66cc being the largest sized among all bicycle engines currently on the market. There are currently no true 80cc engines on the market to date and we want to make you aware of this.