A faulty Spark plug and a discharged battery are the two major reasons for a pit bike not to start. Some other reasons include blockage in carburetor plus oil supply, faulty injection, blocked exhaust pipe.
Since the bike has thousands of spare parts, anything can cause it to fail to start. But there are some common reasons usually found in practice. If you have the basic knowledge of how a bike works, you can easily find out the reason your bike is not starting. However, I will tell you several common reasons that are responsible to prohibit a bike to start.
Main causes of pit bike not start.
- Spark plug fault.
- Battery Fault.
- Inadequate fuel supply.
- Exhaust pipe blockage.
- Dust and sediment in engine Cylinder.
- Mixing rain with fuel in the tank.
Spark plug fault
The spark plug is one of the fundamental parts of the motorbike engine that burn the engine to run. Let's get to know how it works. Before that let me briefly tell you how an engine runs and keeps running. An engine works on a cycle basis. Every cycle has 2 to 4 steps, which you might have heard as 2-stroke and 4-stroke. Ok, that's not our main point. Our main point is how the engine run as we are talking about the reason why engine doesn't start.
The engine is designed to receive air mixed with oil. After that, a piston inside the engine goes up and compresses the mixture of air and fuel to a small amount and space. On that small volume of oil and air, a high voltage AC short circuit is occurred by a spark plug. But this short circuit isn’t caused by the direct touch of the terminal because high voltage sparks when two terminals come near 1 cm to inch.
This causes a big firing and explosion and pushes the piston down. The smoke of the explosion goes out through the exhaust pipe. That's how the cycle ends and begins the new cycle by sucking oil and air. This continuous process causes the piston to go up and down and a connecting rod also moves with it at a rotation shape. This is how the power generated from the engine transmits to the wheel resulting in the rotation.
Now see in the whole process that if the spark plug doesn't have the proper power to cause firing the engine cycle will not start.
A faulty battery with no charge or low voltage won’t supply proper voltage to the spark plug. So a proper ignition will not happen and the engine won't start. So check the battery health and condition. First, check if there is any connection problem. If the connection is ok, you have to check the battery voltage with a multimeter.
Note the voltage rating labeled on the battery. Then connect two lids of the multimeter to the two terminals of the battery. Make sure the red positive terminal of the battery is attached to the red lid of the multimeter and black to black. Then attach the unit selector of the multimeter to DC. You will see the battery voltage on the meter. If the voltage reading is more than one volt less, then you should know your battery isn't at a good state.
A reverse connection to Voltmeter will result in showing a negative value on the screen. But the value should be the same as the positive value. In case of battery voltage down, you can detach the battery from the bike and charge it with a high current battery charger. The voltage of the battery charger can be at most two volts higher than the battery voltage rating. But the Current which is labeled as ampere can be any value higher than the battery ampere rating.
Inadequate fuel supply
Due to inadequate fuel supply, the engine will start to stop. That means it will start and immediately stop. In this case, you will see less exhaust smoke than usual. Check the fuel line and fuel tank. Any blockage to the fuel line to the engine can cause fuel blockage.
Check the fuel tank to understand the amount of fuel reserved. You can shake the bike horizontally to feel the shortage of fuel by the sound of fuel movement. An empty fuel tank will make no sound.
Exhaust pipe blockage
Exhaust is one of the processes of the engine to complete the cycle. If the exhaustion is throttled the engine can’t start. It will stop failing to complete its previous cycle. It’s like a flute that you can’t keep tuning if the other passage is blocked. So check the pipe for any sediment or mud is put into this. But many a time it’s automatically opened with the high-pressure exhaustion from the engine.
Dust and sediment in Cylinder
Sometimes sediment from the fuel tank travels to the engine and then keeps lying there. It causes poor combustion and often product less energy that can't push the piston and continue the engine cycle. That's when the engine can't start. In this case, you have to send your pit bike to a bike mechanic garage for servicing. There is a filter to filter the fuel for any sediment. But due to a faulty broken filter, the dust or sediment can pass in very easily.
Mixing rain with fuel in the tank
Sometimes the fuel tank cap stays loose as a result of what some rainwater pass into the fuel tank mixes with fuel and travels to the engine at intake. Water mixed fuel doesn't burn and explode and so the pit bike engine doesn't start. For this reason, you should always properly close the cap after fueling. Sometimes a soft rubber ring under the cap gets damaged. The cap without this rubber can't be water-resistive and water can drip into the tank.
Since your pit bike isn’t starting, whatever the reason is, it’s always a good idea to take it to a specialized mechanic for the best service. The manufacturer does not recommend to dismantle any component by yourself or any technician out of their service centre. Servicing your bike out of its manufacturer often violates the warranty policy. So if your bike is still under warranty period, you don't go elsewhere for service.