Not getting the mileage you want out of your motorized bicycle? Not getting the mileage you used to when your motor was running tip-top? As gas prices rise, the need to get the best mileage out of each fill-up is vital. If you're burning through fuel more than you used you, it's not only costing you more money at the pump, it could be a sign that your bike engine is in need of some maintenance.
Don't worry, though, because there are steps you can take to help your bike engine run smoother and burn less fuel. A smooth running engine will save you money on gas and repairs. In this article, we'll highlight five helpful tips to improve your motorized bike’s gas mileage.
Properly Break In Your Engine
The first thing you want to do after installing a 2-stroke engine or 4-stroke engine on your bike is break it in the right way. Properly breaking in your motorized bicycle engine ensures that the piston rings are sealed to the engine cylinder. It also allows the walls of the engine cylinder to harden, which will prevent excess fuel from burning.
Failing to properly break in your 2-stroke or 4-stroke engine will force it to work harder, causing unnecessary wear. As a result, the engine will use more gas while running, which will significantly impact your motorized bike’s gas mileage.
Breaking in your 2-stroke engine is a different process from breaking in your 4-stroke engine. We’ve outlined how to properly break in both engine types below.
2-Stroke Engine Break-In
With a 2-stroke engine, you’re going to mix fuel and oil. This fuel-and-oil mixture will differ during and after the break-in period.
To break in your 2-stroke engine, follow these steps:
For best performance, we recommend using a synthetic 2-stroke motorized bike oil, like Maxima Scooter Pro 2-Stroke Synthetic Motor Oil, during and after the break-in period.
Start by mixing the correct fuel-and-oil mixture for your engine.
Most engines require a 16-to-1 ratio, or 8 ounces of oil to 1 gallon of gas. However, some engines ask you to use a lot less, so be sure to use the correct oil-to-fuel ratios, especially at break-in.
The break-in period for a 2-stroke engine is three to four tanks, which is 1 gallon of gas as each tank is around one-fourth of a gallon. Again, you should avoid high speeds and long-distance riding during this time.
Before riding, make sure to warm up your motorized bike for at least one to two minutes. That's to say, don't start from a dead stop too often. When you start your motor, let it warm up with the choke on until the idle raises high enough, indicating your engine's cylinder is warm enough to run without it. After that, give your engine 30 to 60 seconds to idle before hitting the throttle.
Don’t attempt to hit top speeds on your motorized bike during the break-in. When you wind a motor out and give it full-throttle before it's broken in, the parts need to be hardened and sealed. Because they're not at the break-in, they won't be able to handle too much power, and will quickly deteriorate.
You should ride at half-throttle with a top speed of 15 to 20MPH during the break-in period.
Keep initial rides short so you don’t push the engine too much during break-in.
- Initially, try to only use your motor for around 15 minutes at a time, with an hour break in between. After break-in, you can ride for around 30 to 45 minutes at a time with a 3 to 4 hour cooldown in between rides.
After you break in your 2-stroke engine, you’ll switch to a fuel-and-oil mixture of 20-to-1, or 6 ounces of oil to 1 gallon of gas.
4-Stroke Engine Break-In
The break-in for a 4-stroke motorized bike is going to be a little bit easier than it is with a 2-stroke engine. Still, you'll need to be sure to break in your motor correctly, or you're going to find the same problems.
After your 4-stroke engine has gone through this break-in period, you’ll want to switch to a standard non-break-in synthetic oil, like Maxima Scooter Pro Plus 4-Stroke Synthetic 10w30 Motor Oil.
First, it's best to use special break-in oil, such as Maxima Scooter Premium 4-Stroke Petrolium 10w30 Break-In Oil to break in your engine.
Warm up your motorized bike for five minutes before riding.
Don’t go full throttle during break-in and keep your speeds low.
Ride for short periods while breaking in, around 15 to 20 minutes at a time.
A 4-stroke engine can be operated for about 45 minutes during regular use before it needs to cool down, so if you want to reach those distances, make sure you break in your engine properly.
The break-in period for a 4-stroke engine is typically one to two tanks, or half a gallon of gas.
Go Easy on the Throttle
Your bike’s throttle regulates the amount of fuel-air mixture that enters the engine. When you ride at full throttle, you allow much more fuel to enter the engine than usual, which is detrimental to your fuel efficiency and causes lower motorized bike gas mileage.
Fuel usage is directly related to how hard your engine is working. Try your best to keep your speed constant and avoid rapid acceleration in order to maximize your fuel efficiency and get better gas mileage out of your motorized bike. If you lighten up on the throttle, your engine won’t have to work as hard, so it will use less fuel.
If you plan on engaging ¾ throttle for the majority of your ride, you should opt for a 2-stroke engine with an expansion chamber. An expansion chamber helps your engine run smoother and prevents it from working too hard by increasing its volumetric efficiency, thus increasing your gas mileage.
If you know you’ll rarely reach ¾ throttle, a 4-stroke engine will be more fuel-efficient and provide better gas mileage. 4-stroke engines typically have better gas mileage overall, so if you’re not going overboard on the throttle, this type of engine might be the best option for you.
Be Mindful of Your Commute
If you use your motorized bike for your daily commute, you need to keep in mind how your ride will affect your fuel efficiency. Adjusting your throttle for hills, rough terrain, and inclines will affect your motorized bike gas mileage.
In addition, as previously mentioned, if you don't keep your throttle consistent but rather speed up rapidly, this will affect your motorized bike’s gas mileage. Obviously, you’re bound to speed up from time to time, especially if you have a long commute. However, being aware of sudden acceleration is important.
Also keep in mind that 2-stroke and 4-stroke engines differ when it comes to gas mileage. 4-stroke engines have a specific exhaust stroke and, unlike 2-stroke engines, the exhaust is not mixed with the intake. This means a 4-stroke engine typically has greater fuel efficiency than a 2-stroke engine.
Tuning Your Carburetor
Another way to maximize your motorized bicycle’s miles per gallon is to tune your carburetor. Your carburetor controls how much air-fuel mixture gets into your engine.
Inside your carb is a jet that plays a major role in determining your gas mileage. Your carburetor’s jet needle has a significant impact on how much fuel is able to enter your bike’s engine. Fuel enters through the main jet and goes into the needle jet. As the needle moves, it can increase or decrease the opening that allows the air-fuel mixture to enter.
When you move your carburetor’s clip up to lower the jet needle, your fuel mixture will be leaner, meaning it has more air than fuel. When you lower the clip to raise the needle, the mixture will be richer, meaning there will be more fuel than air in the mixture.
Adjusting your carburetor’s jet needle will influence your throttle and thus your fuel use. So if your throttle seems bogged down, you might need to raise the needle. Alternatively, if it operates too slowly, you might need to lower the needle to improve your gas mileage. It is crucial that you find the right setting to ensure that your air-fuel mixture isn’t too rich or too lean.
If you’re still struggling to see improved gas mileage after adjusting the carburetor’s jet needle, you can also increase or decrease the size of your jet. If your engine needs more air (requiring a larger jet) or less air (requiring a smaller jet), it will run inefficiently. There’s a variety of small jets, medium jets, and large jets, so make sure you find the right ones for your carburetor.
Install Parts That Maximize Fuel Efficiency
Aside from finding the right jets for your 2-stroke carburetor, there are other engine parts that can improve your gas mileage.
Note: If you’re being especially conscious about your mileage, you should avoid installing multiple high-performance parts on your motorized bike. Most performance parts actually force the engine to work harder and use up more gas.
A boost bottle kit prevents previously burnt air-fuel mixtures from bogging down your engine. Boost bottles store the used air-fuel mixture rather than resending it to the cylinder for the next intake cycle. This allows the intake cycle to draw fresh air and lets the leftover air-fuel mixture provide a boost to the engine.
Using the vacuum naturally created by your engine’s combustion, boost bottles are able to pre-load fresh air-fuel mixture for each intake cycle. This provides a better overall throttle response and smoother performance so your 2-stroke engine doesn’t have to work too hard.
Without a boost bottle, your motorized bike engine will have a lot of pre-burnt air-fuel mixture in the cylinder, causing it to work harder and decreasing fuel efficiency.
While not directly connected to your motorized bike’s fuel components, a high-performance CDI — compared to a stock 2-stroke CDI — could actually help improve your fuel efficiency.
A CDI is tied to your engine’s spark. With a high-performance CDI installed, you’ll get a better, stronger spark. This means you’ll get a quicker startup, so your engine doesn’t have to stutter to start. In addition, by keeping a strong, consistent spark throughout your ride, your motorized bike won’t bog down.
Getting the Best Motorized Bike Gas Mileage
Conserving gas will save you money in the long run, but a lot of the practices outlined here help you put less strain on your motorized bike, too. Not to mention, if you lower your carbon emissions, you’re also doing something good for the environment.
By keeping the five tips outlined in this article in mind, you can start making the most of your fuel and get the best gas mileage out of your motorized bike.
Photo: BikeBerry (Facebook)