Engine Parts JNMotors Bikes - motorized bicycle parts and accessories
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JNMotorsBikes.com provides an extensive catalog of add on parts and accessories for your motor bicycle. We carry a unique and complete catalog of parts that will allow you to improve or tune up your ride. Each section includes a selective inventory of all available parts for your special build. JNMotors Bikes LLC ships worldwide. If you live outside the USA, learn about our international shipping options.
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#5 66/80cc Piston
Our Price: $11.95
Standard replacement 2 ring Piston. Rings not included. Available for 66c/80cc


Specification
       Aluminum
       Different Specs size

Package Includes
1 66c/80cc
Air filter velocity stack adapter for all of our Walbro carburetor.Allows installation of clamping-style filters. diameter. Increases the air flow on your carb.

Specification

   Velocity Stack 25mm High Raw
   For clamp on style air filters.
   Hole center is 31mm
   Longer intake tract for improved performance.
   Will fit  all Walbro

Package includes
1 velocity stack
1 Gasket
Air filter torque velocity stack adapter for all of our Walbro carburetor.Allows installation of clamping-style filters diameter. Increases the air flow on your carb for torque.

Specification

   Velocity Stack 25mm High Raw
   For clamp on style air filters.
   Hole center is 31mm
   Longer intake tract for improved performance.
   Will fit  all Walbro

Package includes
1 velocity stack
1 Gasket
The 32mm Mikuni Aluminum Ported Billet intake manifold is match ported for perfect gas flow and high performance use on 32mm bolt to bolt cylinder intakes.Recessed holes to countersink allen head screws for a clean install. Made to fit all Mikuni VM 18 Carbs that will fit most china girl motors. Specification Less restrictive flow path from the carburetor to the engine. Improved performance. CNC machined to closely match the intake ported for most engines. Great for racing engines. Design by JCRacing Parts Package Includes •1 Intake
Black vinyl coil-wound housing and Inner nylon sleeve for longer life and smooth operation. Meets or exceeds OE quality.

Specification
•hook style (36 inch total length, 33" Sleeve Length)

Package Includes
1 Complete Cable
The 40mm Mikuni Aluminum Ported Billet intake manifold is match ported for perfect gas flow and high performance use on 40mm bolt to bolt cylinder intakes. Recessed holes to countersink allen head screws for a clean install. Made to fit all Mikuni VM 18 Carbs that will fit most china girl motors. Specification Less restrictive flow path from the carburetor to the engine. Improved performance. CNC machined to closely match the intake ported for most engines. Great for racing engines. Design by JCRacing Parts Package Includes •1 Intake
410 Chain
Our Price: $13.95
415 Chain
Our Price: $15.95
Heavy Duty 410 motor chain, used mostly with 80cc motors. Includes Master Link

Specification
The CLIP style  master links is included.


Package includes
Contains one unit per box
Heavy Duty 415 motor chain, used mostly with 80cc motors. Includes Master Link

Specification
The CLIP style  master links is included.


Package includes
Contains one unit per box
Our new cylinder kits are port and polished to gain the best performance for your motorized bicycle engine. Piston is modified and match with the cylinder to provide the best performance out of the engine. The gasket kit included is design to get the best out of the kit.

Installation only takes 4-5 minutes. It can be used with your stock head and spark plug or with our performance high compression heads (we highly recommend).

This cylinder will make your bike faster, and run more efficient! it will accelerate faster, and go to higher RPM than before guaranty.Altering the port timing changes the RPM where the power -band occurs and increase engine performance.

Cylinder has Intake and exhaust ports ported and polished and and also modified transports.

Package Includes:

1 Ported Cylinder
1
Exhaust Gasket
1 Intake Gasket
1 Set of screws
1 Top Gasket
1 Bottom Gasket
1 Modified Piston Complete Kit

Cylinder head with spark plug hole out at a angle. The inner dome is much smaller than standard which does increase the compression a little bit. 8mm stud holes. Cheapest bolt on to increase performance to any standard motor. Available in 80/66cc and 48cc models only.

Specification
Please select engine size.
Angle Fire 50cc and 80cc option

Package Includes:
1 Angle Head
Walbro carb is design for the 50cc/66cc that are stock. This carb require a special adapter to be use and also a special adapter for the RSE reed kit. The carb has the following features; proper function in any attitude, metering system and fuel pump integrated in the carburetor casting, Adjustable high speed needles, idle needles and idle adjust screw.Meets all CARB and EPA regulations.

Specification
   19mm inlet
   12.75mm venturi
   15.75mm outlet
   2 jets (independent high and low).

   Accelerator system
   Easy Start system
   CARB- approved tamper-resistant designs
   Ethanol-resistant components

Package includes
I carb
Replacement Head Gaskets for 66/80cc or 49/50cc engines.


Package includes

 1  Top Head Gasket for 66cc/80cc or 49/50cc 2-stroke engine kits.
Replacement Clutch Access Cover Gasket for 66/80cc or 50cc between the sides and clutch cover.

Package includes

 1  Clutch Access Cover Gasket for 66cc/80cc or 50cc
Replacement Clutch Mag. Access Cover Gasketfor 66/80cc or 50cc between the sides and magneto cover.

Package includes

 1  Mag. Access Cover Gasket for 66cc/80cc or 50cc
Replacement Crankcase Gasket  for 66/80cc between both sides of crankcase.

Package includes

 1  Crankcase Gasket  for 66cc/80cc
66/80cc Piston Ring
Our Price: $5.95
Replacement Bottom Cylinder Gaskets for 66/80cc or 50cc engines.

MAKE SURE TO SELECT YOUR ENGINE SIZE.

Package includes

 1  Bottom Cylinder Gasket for 50cc or  66cc/80cc 2-stroke engine kits.
Standard replacement rings for stock Piston 66cc/80cc china engine kit.  


Specification
    For 66/80cc motors.
    Different Specs size

Package Includes
2 66c/80cc Ring
Walbro carb is design for the 66/80cc that are stock. This carb require a special adapter to be use and also a special adapter for the RSE reed kit. The carb has the following features; proper function in any attitude, metering system and fuel pump integrated in the carburetor casting, Adjustable high speed needles, idle needles and idle adjust screw.Meets all CARB and EPA regulations.

Specification
   19mm inlet
   12.75mm venturi
   15.75mm outlet
   2 jets (independent high and low).

   Accelerator system
   Easy Start system
   CARB- approved tamper-resistant designs
   Ethanol-resistant components

Package includes
I carb
80cc Cylinder Body
Our Price: $24.95
80cc/50cc Magneto
Our Price: $14.95
Stock 80cc Cylinder Body for China engines.

Specification:

Engine piston barrel. Chrome platted.

Standard Intake Stud spacing: Compatible with Flying Horse and Mega Motors Engines ects.

Package Includes
1 80cc Cylinder Body
Stock replacement CDI (Capacitor Discharge Ignite) takes the electrical charge from the Magneto generator, builds a charge then releases it to the spark plug. Includes the high voltage cap. Stock replacement Magneto sits inside the access cover bolted in. A small magnet attached to crank shaft  spins to generate electrical charge to CDI for spark plug ignition.
It fits all Chinese motorized engine kits.
Aluminum Vent Caps
Our Price: $4.95
SS Socket head cap screw hardware. This hardware allows you to use allen wrenches for all your case covers and head-bolts plus provide with better tensile strength then the original screws.

Please Note that some engine kits uses 8mm fine thread head bolts. The supplied head bolts will not work on the head. The rest of the screw work on all types of engines.


Specification

4 X Course Thread Head Bolt W Flat and lock Washers

5 X Clutch Cover

4 X Magneto Cover

3 X Sprocket Cover

4 X Ny-Lock Nut for Motor Studs

4 X Intake and Exhaust w Flat and Lock Washers

Package Includes
1  SS Socket Head Cap Screw Upgrade Hardware Kit
Aluminum Ported Billet Intake intake manifold is  match ported for perfect gas flow and high performance. Grooved at the tip with an O ring for a nice air tight fit. Recessed holes to countersink allen head screws for a clean install. Made to fit all NT , Speed and most standard Carbs and will fit most motors.

Specification
 
   Less restrictive flow path from the carburetor to the engine.
   Improved performance.
   O-Ring seal eliminates vacuum leaks that cause poor idle quality.
   CNC machined to closely match the intake port on most engines.

Package Includes
•1 Intake
•Complete new hardware
Note:If you are able to mount your engine at a level attitude this Intake is for you!
The Aluminum Vent Caps come and 5 different colors. The Vent Caps help fuel flow on your tank by providing a more uniform air flow in side the tank.
If you have been experiencing problematic performance from your motorized bike and you suspect it's the carburetor, here's a chance to satisfy your curiosity and put your mind to rest! Install this brand new complete carb with performance filter and velocity stack on you 2 cycle engine in an effort to get the performance you want. This newly revised carburetor incorporates a larger barrel slide throttle body for increased performance.

Specification
Sealed Ball Bearing Chain Idler Pulley and Shaft
Will fit either bracket

Package includes
Includes one unit per box.
This is the adapter that mounts onto the cylinder on the 50/66/80cc engines.

Specifications:
High quality aluminum
Made in Australia

Package includes
1 Barrel Adaptor
 hardware
1 gasket

Note that no carb or extra part are included !!!
Newest available! This head adds HP and a classic  bad ass shovel-head
look. This aerospace quality aluminum head not only looks cool, it keeps
your engine cool and bumps up compression. With Loads of fin surface
area, it wicks away heat effetely. Squish-band design seats the head perfectly into the cylinder funneling
gasses precisely to the combustion point at the spark plug, increasing
efficiency and reducing potential detonation; a condition where hot
spots in the engine cause the fuel to combustion in unwanted areas such as
under the piston, or at various undesirable points inside the chamber.
Correct compression will not only increase power, but cooling as well.    Specification JCR High Compression Head
Billet Aluminum Design
Made in the USA

Package Includes
1 High Compression Head
Centrifugal Clutch kit
Our Price: $39.95
Chain Guard (Black)
Our Price: $5.95
Chain Guard (Chrome)
Our Price: $9.95
The Centrifugal Clutch kit fit almost any Chinese 2 Stroke bicycle motors. With this kit installed converts your engine from a manual to a full automatic chain drive and you can keep your engine running without having to worry about clutching.

Specification
•Automatic Centrifugal chain activation
•No lubrication is require

Package Includes
1. Clutch Assembly
2. Clutch Covers
3. Screws and Tools
Black chain guard for your special builds. Protect your leg from the moving chain.

Specification

Chain Guard  for motor drive sprocket


Package includes

1 Black Chain Guard
Add a new look to your build with the chrome upgrades. Pimp your ride with the chrome chain guard give it a nice unique look.

Specification

Chain Guard  for motor drive sprocket


Package includes

1 Chrome Chain Guard