A motorcycle (or any vehicle) should generate more power when you twist the throttle cable. But, sometimes, it goes reversely due to various reasons. It could be risky if your motorcycle is losing power when accelerating or not responding to your throttle when going uphills.
In this guide, we’ll investigate why your motorcycle is losing power when accelerating. I’m sure my engineering background and years of experience will help you rectify the actual cause and fix the problem.
So, why is my motorcycle losing power when accelerating? Your motorcycle is losing power because of the old or dirty spark plug, clogged air filter, dirty carburetor, bad gas quality, extra slack in the throttle cable, faulty oxygen sensor, vacuum leak, and clogged fuel injector.
Fortunately, you can fix these problems yourself without going to a mechanic. Read on to learn how to rectify the actual cause and fixing process.
Table of Contents
- 1 7 Reasons Your Motorcycle Losing Power When Accelerating
- 2 Why Is My Motorcycle Loses Power When Going Uphill?
- 3 Why Is My Motorcycle Loses Power When It Hot?
- 4 Why Is My Motorcycle Delayed Throttle Response?
- 5 Why Is My Motorcycle Losing Power And Backfiring?
- 6 Why Is My Motorcycle Losing Power At High RPM?
- 7 Conclusion
7 Reasons Your Motorcycle Losing Power When Accelerating
Here are seven common reasons that cause power loss problems on a motorcycle. Thankfully, you’ll be able to fix these problems yourself, and you don’t need to see a mechanic for this.
I’ll explain them along with symptoms and easy fixes.
1. Bad Spark Plug
I’m sure you know the importance and function of a spark plug in a gasoline engine. A spark plug ignites the air-fuel mixture in the combustion chamber. If it fails to generate a spark for any reason, your motorcycle will not start.
In most cases, a dirty spark plug is the primary reason your motorcycle loses power when accelerating. That’s why regular check-ups and cleaning are necessary for smoother rides.
If your motorcycle’s spark plug is too old or damaged, it causes power loss and delayed throttle response.
Symptoms: The common symptoms of a bad spark plug are engine starting problems, poor acceleration, and misfiring.
How to fix: Clean the tip of the spark plug or replace it with a new one (if it’s older than 2 years).
2. Clogged Air Filter
The air filter is the nose of your motorcycle. It sucks air from the environment and supply to the carburetor, where gasoline is mixed in the correct ratio before supplying it to the combustion chamber.
If you ride your motorcycle in dusty environments, the dust particles clog the air filter’s pores, restricting oxygen flow.
Lesser oxygen supply results in incomplete combustion, and your motorcycle may lose power and backfire.
Symptoms: The symptoms of a clogged air filter are reduced mileage, power loss when accelerating, and black smoke from the motorcycle exhaust.
How to fix: Clean the air filter with a blower or replace it after 10000 to 12000 miles or if it’s older than 12 months.
3. Dirty Carburetor
The function of a carburetor is to maintain the air-fuel ratio. It mixes the fuel before supplying it into the combustion chamber.
However, dust particles accumulate over time and block the carburetor. This disturbs the air-fuel ratio at higher rpm, and your motorcycle feels like losing power when accelerating.
Symptoms: The most common symptoms of a dirty carburetor are backfiring, running too lean, running too rich, and feeling like your motorcycle is losing power while accelerating.
How to fix: Clean the carburetor with WD 40 or any degreaser.
4. Bad Gas Quality
The quality of gasoline affects your riding experience. If you’re using low-quality fuel in your motorcycle, it won’t generate enough power to reach the top speed.
Many gas filling stations offer ethanol-blended gasoline at a lower price. Ethanol attracts moisture over time, which dilutes the gasoline, and your motorcycle will run poorly.
If you’ve stored your motorcycle for over 30 days, you’ll face a power loss problem when accelerating. You must empty the tank and refill a good-quality gas for a smoother ride experience.
Symptoms: The symptoms of bad gasoline quality are poor engine performance, exhaust misfire, and black smoke from the exhaust pipe when accelerating.
How to fix: Empty the gas tank and refill good-quality gasoline at the reputed filling station.
5. Extra Slack in Throttle Cable
Your right handlebar is connected to the throttle valve by a throttle cable. When you twist the handlebar, it opens the throttle valve and increases the air supply. However, you must have noticed some slack (free play) to maintain the
Symptoms: Your motorcycle will not reach the top speed and will lose power on acceleration.
How to fix: Adjust the extra slack or replace the throttle cable.
6. Faulty Oxygen Sensor
An oxygen sensor on the exhaust pipe measures the amount of unburnt oxygen. It communicates with the electronic control unit (ECU) to decide the right air-fuel mixture for the best engine performance.
The motorcycle’s ECU collects these data and decides the right fuel supply amount for optimum performance. If your oxygen sensor is faulty, ECU will not get the correct data, interrupting the fuel supply at a higher RPM.
Symptoms: The common symptoms of faulty oxygen sensors are poor acceleration, black smoke from the exhaust pipe, stalling, rough idling, engine misfire, and check engine light.
How to fix: You need to replace the O2 sensor and reset the ECU.
7. Clogged Fuel Injector
Fuel injectors have replaced the carburetor in all modern motorcycles because of their higher efficiency and better engine performance. The fuel injectors are controlled by the engine control unit (ECU). However, bad-quality fuel or rusting gas tanks may clog the fuel injector nozzles.
A clogged fuel injector could also result in poor acceleration and power loss at higher RPM. So, inspect your fuel injector and unclog it for proper functioning.
Symptoms: The common symptoms of a bad/clogged fuel injector are engine misfire, power loss when giving throttle, engine starting problems, low gas mileage, and dancing rpm needle.
How to fix: You must clean/unclog the fuel injector or replace it. Always use OEM parts on your motorcycle for performance and reliability.
Why Is My Motorcycle Loses Power When Going Uphill?
If your engine is revving at higher rpm, but the motorcycle is losing power while going uphill; this is a sign of bad clutch plates. Your motorcycle will lose power uphill because of friction lining wear and clutch slippage. To fix this, you must replace your clutch plates and cable.
Why Is My Motorcycle Loses Power When It Hot?
A faulty rectifier and a bad ignition system are the primary reasons your motorcycle loses power when the engine is hot. Overheating causes preignition/knocking that leads to power loss. To fix this, check your motorcycle’s engine oil quality and level. If the oil has blackened or burned, please replace it immediately.
Why Is My Motorcycle Delayed Throttle Response?
A too rich air-fuel mixture and carbon fouling on the spark plug are the most common reason for delayed throttle response. It happens because of a clogged air filter, a bad oxygen sensor, a faulty throttle position sensor (TPS), and poor carburetor tuning. You need to inspect all these parts to rectify the real cause. I would recommend you visit a mechanic shop for carburetor tuning.
Why Is My Motorcycle Losing Power And Backfiring?
I recently fixed this problem on my Honda CBR650-RR. Your motorcycle loses power and backfires when the engine runs too rich. When the unburnt hydrocarbons come in contact with oxygen, they ignite and cause a loud sound on the exhaust pipe.
It happens because of a clogged air filter, faulty O2 sensor, and bad spark plug. To fix this, inspect these parts and replace the faulty ones.
Why Is My Motorcycle Losing Power At High RPM?
A faulty spark plug, ignition coil, and low battery voltage are the most common reasons your motorcycle loses power at higher rpm. It happens because your spark plug cannot ignite the air-fuel mixture at higher rpm. Please ensure to inspect, maintain, and replace the critical ignition system components during routine service intervals.
These are several factors that cause power loss during acceleration. The most common cause is a bad ignition system. So, please inspect your spark plug, ignition coil, regulator-rectifier unit, and oxygen sensor. I recommend you replace your spark plug and air filter every 12 months for better performance.
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