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Operation and Maintenance of Your Motorized Bicycle

HOBBY. Gas bikes are for those who like to tinker, build and work on their own bicycle. These bikes are kits and not meant for consistent, reliable use. You have to maintain them regularly. Bolts come loose and the 2-strokes depend on un-burned oil for lubrication. That means they can be oily and messy. Approach your bike like a hobby and you will be pleased with the results. Beware, these engines come in myriad variations and levels of quality. Generally, the less you pay, the lower the quality. 

BREAK-IN PERIOD. All new gas bike motors require a break-in period. Break-in is 100-150 miles or five-ten hours. During this time, you need to run the motor with a special break-in 2-stroke oil, mixed at 20:1 (that's 6 1/2 ounces of oil per gallon), (for 4-stroke, special crankcase oil). If not break-in oil, then use 16:1 (that's 8 ounces of oil per gallon of gas). We recommend only using Dumonde oil, especially during the break-in period. We carry Dumonde Tech oils. Dumonde Tech Break-In Oil is designed for proper Break-In on any type of engine. Proper Break-In determines both the short-term life and longevity. It helps the rings seat properly and the cylinder walls to harden. Dumonde Tech Break-In Oil is a very complex formula that allows proper ring seat, work hardening, while impregnating parts with a matrix compound film to protect surfaces against lean periods and corrosion. Through research it has been found that a high percentage of these processes are not achieved with conventional oils. By not achieving these effects, performance and durability can be greatly effected. 

RUNNING. During break-in, do not run the motor for extended periods at a constant speed and do not run at full speed. Target less than 20mph and less than 30min. Always take a few minutes at an easy, unloaded, speed to warm up (3-5 min). On cold days, use about 3/4 choke to start (up is choke on and down is choke off). Learn to turn the choke off while going slowly. On warmer days, no or little choke is needed. For the first few rides, make them shorter and take time after each ride to inspect the bike, tighten all the bolts and chain and make sure everything has settled in for the long-term.

2-STROKE OIL. After break-in, continue to use synthetic oil at 32:1 (that's 4 ounces of oil per gallon). Using synthetic oil extends the life of the motor and makes less smoke. Do expect some burned oil accumulation at the tail pipe (residue). This is normal. If you use regular 2-stroke oil, run at 20:1 (6 1/2 ounces per gallon). The typical "peanut" gas tank that comes with most gas bike kits are 1.5 Liter or 0.4 gallon (51oz). (In a pinch, that's 2.6oz of regular oil or 1.6oz of synthetic.) It is not recommended to mix the gas in the bike's gas tank. It's difficult to calculate the right mixture because residual pre-mix remains in the tank and you may not get a good distribution of oil before running.

4-STROKE OIL. On your 4-stroke crankcase oil, use a good quality, 4-stroke-specific, motorcycle oil. 15-40 is fine, such as the Dumonde GP4 and the Dumonde  B4 break-in oil for the first 100-150 miles (or five-ten hours) of operation. Synthetic is always a good choice. For best longevity, change the oil every 10 hours of use. This will ensure top performance and wear at all times. It doesn't hold much oil and has no filter, so it is best to change it often. 

FUEL. It is best to select a small gas can to mix your fuel. The best choice would be a red, steel, 2-gallon storage can, Certified by FM, UL/ULC, and TUV. This will keep your fuel fresh and safe for at least six months. Use fresh premium gas on 2-strokes. Regular is fine for the 4-strokes. A plastic container, certified for gasoline storage is OK, but the gas will need to be used in less than three months. Mixing in a gas can also lets you be more precise on your oil measurement. 

2-STROKE STARTING. To start the motor, set the choke and turn on the gas. Squeeze the clutch and hold the throttle at 1/4 open. Pedal the bike up to at least 5mph. Release the clutch in a smooth continuous motion. If you slow too much before the engine starts, start over. Allow the engine to warm up at around 10mph. Running at 20mph allows the combustion chamber to stay hot and the motor to stay in the optimum power level (best gas mileage too). Avoid idling for more than a minute or two. Un-burned oil accumulates on the spark plug at an idle and could foul the plug (engine will not run). Idling puts excess strain on the clutch and the lack of air flow could overheat the engine. If you come to a stop light, use the clutch. If the wait will be a while, stop the engine. Never run the engine at speeds under 5mph (lugging). Most riders get in excess of 75 miles per gal of gas. 

2-STROKE ELECTRICAL. For proper operation, the spark plug should be clean and not fouled by oil. The gap is 0.14. Use a B5HS or B6HS model plug. The magneto provides the electrical pulse to the CDI for a spark. The magneto should measure around 300 to 400 Ohms while disconnected. Always ensure the magneto is dry and the mounting bolts secure. Check for frayed or grounded wires - especially leaving the housing. Your CDI inputs should have a low resistance, around 10 Ohms, but you may need to make measurements with the "diode" setting to ensure accurate readings with a digital VOM. Checking for spark: With the gas turned off and the carburetor bowl empty, check for spark in a dark area by removing the spark plug, grounding the side of the plug, and turning the engine over rapidly. Make sure the connections are good throughout the chain, black wire is connected to black wire, and no pinched wires. Disconnect the kill switch wires to make certain they are free of grounds (test with them on and off). You should see a sharp blue spark on every revolution.   

SMOOTH STARTS ON ALL BIKES. Do not use the clutch to start from a stop. The clutch on these motors is not suitable for standing starts. In all cases, when starting from a stop, pedal to get some speed and, while pedaling, release the clutch in one smooth motion, after you reach 5mph. For 4-strokes motors with an automatic clutch, slowly twist the throttle as you gain speed.  Continue to pedal for a bit to help the motor achieve solid operating speed (about 10mph). Two-stroke motors have a power band that hits at higher RPMs. At lower RPMs (and especially at idle) the motor will tend to foul or "load-up." Once you hit the power band, the motor will "clean-out" or begin to run stronger and smoother. Lugging the engine should be avoided, as this will cause the engine to load up. These are not motorcycles. The motor is to help you sustain speed only.

2-STROKE CARBURETOR. It is absolutely essential that the carburetor be fully seated and have no air leaks. A poorly installed or loose fitting will greatly effect operation and adjustment. Worse, air leaks can cause a lean mixture and damage the engine. Periodically, check your intake and exhaust bolts for a snug fit, as these may vibrate loose over time, especially during break-in. You cannot diagnose or adjust the fuel system unless all the fittings are seated and sealed. 

Normally, all the carburetor settings do not change. The air screw on the side of the body of the carburetor adjusts how much air mixes with the idle circuit (Idle Adjuster). The standard setting is 3 1/2 turns out from fully seated. On the NT-style carburetors, the air screw is very a very simple design. Screwing the adjuster in makes the idle speed faster and richer (too far and the bike will load up and stall). The idle speed is set by adjusting the screw for optimal idle - just fast enough to not stall out. The cap Cable Tension Adjuster nut adjuster and throttle handle adjuster are used to take up the slack in the throttle cable and can be used to hold the idle. Because the throttle cable comes manufactured at a fixed length, all the pieces from the throttle tube down to the cap nut and slide must be correct or you will be too short or long to make adjustments. If any of these pieces become worn or damaged, they must be replaced to accurately adjust the idle. Use the Primer on cold days. If you are an advanced mechanic, look at your spark plug to gauge the running mixture. Move the clip on the jet needle up to lean out the mixture or down to make it richer. Check your spark plug after running at 20mph, at full operating temperature, for at least 1/2 a mile. It should be chocolate brown. If it is dark and oily, you may need the B6HS (hotter) plug or a leaner mixture. If it is white or very clean looking, you may need to make the mixture richer (lower the clip on the needle). Warning: Running a lean mixture may damage your engine.

PARTS AND UPGRADES FOR 2-STROKES. The most effective way to improve throttle response, low-end power, torque and horsepower, is to add a few hop up parts to the fuel and exhaust system. An upgraded carburetor with better machined internals is a good starting point. Adding a reed valve will dramatically improve low-end and throttle response. Replacing the stock muffler with an expansion chamber will improve horsepower and torque. After you do those changes, you may want to change the standard 42T/44T rear sprocket to a 32T/36T. When parts break, many are available, but sometimes it is cheaper just to throw the engine out and replace the whole thing. After all, a complete kit is under $300 and you can get engine-only kits for even less. 

SPARK PLUG & AIR CLEANER MAINTENANCE. On all bikes, replace your spark plug every 500 miles or 25 hours of use. You may go longer, but do risk poor combustion or a fouled plug. Clean the air filter every 100 miles or five hours. Clean it with solvent (paint thinner or kerosene) and do not oil it. Replace the filter whenever it becomes torn or ragged.

BEFORE YOU RIDE. Before every ride, check bolts on both the bike and motor for proper tightness. Do not over-tighten bolts as they do strip easily. If you have spoke wheels, check every spoke for tightness, especially on your rear wheel. (Note: starting off smoothly vastly improves wear on rear spokes.) Oil your chains with Dumond Tech chain oil as needed (usually every 100 miles). Wipe them clean after oiling. Check and adjust the chain tension. Riding any bike carries with it some risk of injury. Remember, you are responsible for the safe operation of of your bike. Take time before every ride to ensure it is safe to ride. Wear a helmet. 

CLEANING. To clean the bike, spray with a good degreaser, scrub and wash with warm soapy water. Sprinkle the soapy water off, never spray. Keep water out of the exhaust port and carburetor. It is best to bag the carburetor prior to washing. If you operate the bike in the weather, rinse it off after you get home. Water gets into the bearings, so keep it clean and dry after use.

TUNE UP THE BIKE. Every year, or sooner if you ride a lot or in the weather, give the bike a good cleaning. This would include servicing all the bearings (wheels, headset, crank, chains, tensioner, brakes, etc.). Usually, the engine only needs the air cleaner and spark plug checked. Keep water out of the engine area or be very careful not to spray water into the engine area.   

STORAGE. ​Store your bike in a covered, well ventilated area, suitable for a gas-operated vehicle. Never bring it indoors or into a living space. Always shut off the gas tank petcock (item #4 in the exploded view). For extended periods of storage, carefully drain the carburetor bowl and dispose of the fuel properly. Premixed gas may be stored up to six months if it is in a steel can with little or no air space. 

WEAR. Over time, your engine will degrade and lose power. These engines, if operated properly as described above, will last 200 or more hours. When they do wear out, it is usually far cheaper to just replace the engine. Engine-only kits are less than $200. 

A Note of Caution From the Manufacturer and Archer's Bikes

Disclaimer: Operating a motorized bicycle and/or bicycle engine kit carries a risk of serious bodily injury. All gas bikes may be dangerous to operate. They are effectively a toy or hobby kit. Archer's Bikes does not manufacture or assemble any of these gas bike parts. All warranties are from the manufacturer only. The rider accepts responsibility for any and all vehicle operation that may lead to personal injury, economic loss, social distress, other losses, costs and damages. Archer's Bikes is not responsible for injuries and/or damages resulting from operating this motorized bicycle or bicycle engine kit. In other words: you are on your own when operating a gas bike, be careful and always wear a helmet.

Disclosure of accurate engine size: While we have chosen to use the long standing factory branding engine size of "80cc," the true displacement of the bicycle engine is 66cc. Down through the years China bicycle engine manufactures have advertised their biggest engine as 80cc, therefore we have listed them in the same way on our website. However, the bore and stroke of an 80cc being 47x38mm equals 66cc. Therefore the true displacement of the 80cc bike motor is 66cc. In the west, the volume of a cylinder is calculated by using the formula Volume = Pi x Radius Squared x Stroke. However, in the east the displacement of an engine includes the area of the cylinder head's combustion chamber as well as the volume of the cylinder. Therein lies a discrepancy between measuring standards by the manufactures in China with those in the United States. However, all "80cc" engine kits on the market today are actually 66cc in displacement size if measuring by US standards.

​​​LIMITED WARRANTY

EXCEPT AS SET FORTH HEREIN AND WHERE APPLICABLE, NO WARRANTY OR AFFIRMATION OF FACT OR DESCRIPTION, EXPRESS OR IMPLIED, IS MADE OR AUTHORIZED BY ARCHER MOTORSPORTS, INC. (dba Archer's Bikes). ARCHER MOTORSPORTS, INC. DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS. ARCHER MOTORSPORTS, INC. ALSO DISCLAIMS ANY LIABILITY FOR CLAIMS ARISING OUT OF PRODUCT MISUSE, IMPROPER PRODUCT SELECTION, IMPROPER INSTALLATION, PRODUCT MODIFICATION, MIS-REPAIR OR MISAPPLICATION. Archer Motorsports, Inc. warrants any used Vehicle, described on your sales receipt, for 30 days from the date of purchase for mechanical defects that existed prior to Customer possession. Used Vehicle warranty only covers the labor to repair defect, parts are extra. In any case, Warranty does not cover damage to the frame, fork, rims, or flat tires. The warranty does not cover user negligence. Customer accepts any used Vehicle purchase “As-Is” and agrees that he/she has fully inspected the vehicle to his/her full satisfaction prior to possession. Archer Motorsports, Inc. warrants any new Vehicle for one year from the date of purchase for mechanical defects that existed prior to Customer possession. Any mechanical defect found by Customer after taking possession—other than those caused by customer or by the negligence of the customer or as the consequence of others—during the warranty period, will be repaired at no labor cost to the Customer. Repair or replacement parts are not included or covered by the warranty, except for those replaced by the manufacturer under manufacturer’s warranty. All warranties are made void in the event any repair performed by Archer Motorsports, Inc. has been tampered with, altered or repaired by any person not expressly authorized by Archer Motorsports, Inc. or repair that is made by any other party not specifically authorized by the manufacturer. Customer agrees and understands that any type of repairs are no guarantee for Vehicle operability or performance. Archer Motorsports, Inc. may repair or reject a warranty claim, replace defective parts (with new or used parts), or refund the cost of a previous repair or part, at its sole discretion, for defects covered by this warranty. Limited Warranty only applies to purchases over $500 for motorized and over $100 for non-motorized vehicles. 

​ACKNOWLEDGEMENT OF RISK AND LIMITATION OF LIABILITY

Customer understands that using a Vehicle, especially off-highway, has inherent risks of injury to the Customer or others. Risks of injury include, but are not limited to, minor bumps and bruises, major injuries or even death, and as such, Customer certifies that he/she/they are fully competent and skilled to operate the Vehicle under all conditions. The Customer hereby acknowledges that operating Vehicles on trails and roads with or without other like vehicles and riders is a dangerous activity, with a high risk of serious bodily injury or death to Customer/passengers/riders or others. Any liability for incidental, special, exemplary, punitive, direct or indirect damages, special or consequential damages including, but not limited to, damage or loss of other property or equipment, loss of profits or revenue, cost of capital, cost of purchased or replacement goods or any claims of customers of the Purchaser as a result of operation or use of the Vehicle or merchandise is expressly disclaimed to the extent permissible. In any event, any and all claims for damages shall be limited to the value of the purchase price that gives rise to any liability. The Customer and any other operators/passengers/riders or others hereby personally accept all risks and liabilities of any and all activity associated with the Vehicle or merchandise. It has been explained to the Customer and he/she/they understand that by signing this document he/she/they are giving up important legal rights. It is Customer’s further intention to give up those rights and in good faith to relieve, release and indemnify Archer Motorsports, Inc., its employees, agents, shareholders, directors and officers, Vehicle manufacturer, of any duty legally owed to Customer in relation to the conduct of this activity or operation of the Vehicle. Customer agrees to follow all applicable laws governing the operation of the Vehicle, on-road or off-road, in a safe and responsible manner, to regularly check the Vehicle for proper mechanical operation and maintenance and to follow any of the manufacturer’s guidelines. 

Gas Bike FAQs
All you need to Know

Dumond Tech 2-stroke break in oil

GAS BICYCLES - INFORMATION AND FACTS

​​​​Mixing Your Gas and Oil

If you want to mix the oil right into your tank at the gas pump (not recommended), use the chart at the right. This will help you decide how much oil to add directly to the tank. For example, if you pump in 0.4 gallons of gas, you would add about 1 1/2 ounces of synthetic oil or 2 1/2 ounces of regular 2-stroke oil. Mix it as best you can by tilting the bike a few times. The chart is rounded up to help you measure right from the site gauge on the bottle. It's hard to measure small quantities precisely, so error on the side of extra oil versus too little. Don't over do it though. Too much will cause excess smoke and residue buildup and could foul your spark plug.

NT Carburetor

​​​​​​Motorized Bicycle Regulations in Arizona - Frequently Asked Questions

Before you ride, review your town’s bicycle laws. This is not a legal opinion or comprehensive evaluation of the law. Consult a lawyer or other professional for any official interpretation. 

What is a motorized bicycle?

The precise definition of a motorized bicycle is not well defined in Arizona. As well, every county, city or town may impose or interpret regulations differently. Generally, a motorized bicycle means a bicycle or tricycle that is equipped with a helper motor that has a maximum piston displacement of forty-eight cc or less (under 750 watts or one Hp), that may also be pedaled, and that is operated at speeds of less than twenty-miles-per-hour. Over this limit would be a motorcycle, ATV, scooter or even a moped (moped laws usually revolve around a 28-25mph limit and additional equipment requirements - lights, horn, brake light, etc., but must have pedals as an option).Local law enforcement is always free to stop anyone that is operating a vehicle unsafely.It is ultimately up to the operator to ensure he or she is in compliance with the laws and regulations and are operating the vehicle in a safe manner. As with any vehicle, motorized or not, you must obey the traffic rules and laws, observing and yielding to traffic control lights and markings - and traveling in the same direction as traffic. Never ride on pathways reserved for pedestrians or those that specifically prohibit motorized vehicles.

Every jurisdiction is different, but in general, the following may apply:

  • A driver’s license is generally not required to operate a motorized electric or gas powered bicycle or tricycle.
  • A certificate of title and registration is not usually required for a motorized electric or gas powered bicycle or tricycle, which avoids a vehicle license tax or plate.
  • A motorized electric or gas powered bicycle or tricycle, as described above, would be exempt from vehicle emissions inspections.
  • By definition, a motorized electric or gas powered bicycle or tricycle may use rights-of-way designated for the exclusive use of bicycles. In general, motors should be under 49cc to qualify and not exceed 20mph. In Arizona, this classification is poorly defined.
  • You must obey all traffic laws. Be courteous, ride in the bicycle lane or as far to the right as possible, and yield to others as appropriate. Never ride on the sidewalk. Sidewalks are for pedestrians only.  (however, purpose-built bike paths may be very much like a sidewalk).
  • Although you can register your Motorized Bicycle with the DMV, allowing you to operate your vehicle on the road like a motorcycle or moped, you will have to have insurance, registration, motorcycle endorsement, and required equipment (such as tail and headlight, brake light, mirror, etc.). This also means that you cannot, by definition, ride on any bicycle lane and must stay on the roadway.


We strongly recommend:

  • Install a speedometer, if the bike does not currently have one.
  • Always wear a Helmet - under 18 must wear a helmet.
  • Wear goggles or appropriate glasses to protect your eyes.
  • Install a mirror.
  • Install a bicycle headlight and tail light.
  • Wear appropriate, close-fitted, clothing, gloves and shoes for safety.


Operating a motor assisted Bicycle on the street

To be as safe as possible in regards to the law, keep your speed under 20mph, stay out of motor vehicle traffic lanes, use bike lanes as appropriate, yield to pedestrians, obey all traffic laws, wear a helmet and be courteous. In Arizona, Law enforcement may interpret your riding how they see fit, considering public safety first.

Dumond Tech Synthetic 4-stroke oil

​​​2-Stroke Pre-Mix Gas Bike Oil and Break-In Process

Dumonde Tech Break-In Oil is specially designed for proper Break-In on any Two-Stroke engine. Recreational or Race, proper Break-in determines both the short-term life and long-term performance of all gas bike engines. Using Dumonde Tech Break-in Oil, and their procedure, gives an inexpensive performance gain over other brands and dramatic improvements over conventional oils. Generally, pure synthetic oils should not be used to break in an engine either, as they do not contain the special products to effectively coat the moving parts. The proven, complete break-in procedure, is printed on each bottle of Dumonde break-in oil. For gas bike engines, during break in, this 4-ounce bottle would mix up 0.6 gal (or 77 ounces of pre-mix gas). After break in, use Dumonde synthetic 2-stroke racing oil at 20:1 or 4oz per gallon. You'll get longer engine life, better gas mileage and less smoke and residue. 

Dumonde Tech Break-In / Storage Oil is a very complex formula that allows proper ring seat, work hardening and it impregnates parts with a matrix compound film to protect surfaces against lean periods and corrosion. Through research it has been found that a high percentage of these processes are not achieved with conventional oils. By not achieving these effects, performance and durability can be greatly effected.

Benefits: Measurable increased performance gains - Less engine failure - Greater cooling - Increased protection of parts against corrosion

Note: never use anything but 2-stroke oil. Using an oil that is not meant to be burned pollutes and leaves behind nasty residue in your engine. Worse, it does not lubricate the engine parts very well. 

Dumond Tech Synthetic 2-stroke oil
Dumond Tech 4-stroke break in oil
NT Carburetor exploded view
BBR 4-stroke complete bike

Read about Gas Bike FAQs and get all you need to know about gas bikes, specifications and facts. Find the right gas bicycle for you. 2-stroke & 4-stroke.

gas bike Gas-Oil mix ratio chart

4-Stroke Gas Bike Oil and Break-In Process

Dumonde Tech B4 Break-in Oil, and proven break in process, is developed for proper break-in on any Gas Bike/ATV/Motorcycle, Four Stroke engine. Recreational or Race, proper break in determines both the short term life and performance of all engines.

Dumonde Tech B4 is a very complex formula that allows proper ring seat, work hardening and impregnates parts with a matrix compound film to protect surfaces against lean periods and corrosion, in part by modern fuels, which are increasingly acidic.

Through research R & D, it has been found that a high percentage of these processes are not achieved with conventional oils. By not achieving these effects, performance and durability can be greatly effected. Following a proven break-in process assures maximum life from your Gas Bike engine.

Benefits:

  • Increased performance gains
  • Less engine failure
  • Greater cooling
  • Increased protection of parts against corrosion

Electric Bicycle Information  

Dollar-for-dollar, Gas bikes generally cost less and are more powerful than an electric bike. Gasoline contains 125,000 BTUs of energy per gallon (36,650 watt-hours). That's a lot of energy and, at $2.50 per gallon, very cheap energy. Unfortunately, gas engines are very inefficient. Energy is lost in un-burned fuel, heat and friction. Electric bicycles come with an electrically-driven motor. Like gas motors, the electric motor is used to provide extra pedaling power to the bicycle.  Electric bikes do cost more than gas bikes, but are clean and friendly to the environment (a typical electric bike holds 500 watt-hours of energy). E-bikes convert the stored energy far more efficiently than a gas bike. On an e-bike, the rider may use the motor to assist in pedaling or use the optional throttle, reducing the effort used to move the bicycle. All electric bikes have the option of turning off the motor and even leaving the battery at home, making the bike a traditional pedal bike. For more on this topic, go to the Electric Bike FACs page. 

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