Nitro Engine Stalls When Accelerating [Troubleshooting]

The engine keeps stalling your brand new RC nitro engine. Feeling frustrated at not being able to race with your RC. Fret not, we’re here to help.

Wondering how to fix nitro engine stalls when accelerating?

There are multiple possible reasons why it’s happening. It could be a needle issue where the fuel is too rich. There’s a chance that the fuel injection is blocked or there is a leak in the fuel intake. There being too little fuel may also result in the engine stalling

Don’t worry, the issue can be solved really easily. We’re here to walk you through the root of the problem. 

Why is the Nitro Engine Stalling When Accelerating?

There are a few prevalent causes why the engine stalls. Many nitro affiants, including yourself, have dealt with the problem and devoted hours. We’ll break it down into a few reasons and propose remedies for each. Let’s look at the most common explanations.

Reason # 1 Faulty Glow Plug

If the engine stalls when accelerating, the glow plug is often faulty. The ignition for the fuel is provided by RC glow plugs. As a result, it is logical that not working can result in issues such as stalling. 


Replace the faulty glow plug with a brand new one. Glow plugs can be found easily by looking them up online or visiting your nearby RC store.

Reason 2: Fuel Flow Blocked

If fuel isn’t flowing without blowing through the pressure line then there might be an oil problem. There may be foreign substances in the line which will cause pressure line problems. It could be that a piece of stone got stuck.


Ensure that all the fuel lines are clear and free of holes. Examine the carburetor fuel inlet and high-speed needle seat for dirt buildup. If you notice stones and soil on the needle, clean it immediately using a soft-bristle brush and EFI cleaner. Check the exhaust seals on the header, and connection between pipe and header

Reason 3: Carburetor Incorrectly Adjusted

The engine’s carburetor may have been adjusted incorrectly. It usually happens when cleaning the engine or adding fuel. 


Change the carburetor to factory settings and tune the engine for performance. First, oil the air filter to keep dirt out. Then, 2 3/4 turns counterclockwise, turn the high-speed mixture screw.

Reasons 4: Air Bubbles

An air bubble in the fuel line is blocking the fuel supply. This happens usually if there are leaks anywhere in the fuel line. Purchase a Bulk fuel line the next time. They are more durable.


Check your fuel lines for holes by taking them off and submerging them in water. Connect one end and blow in the other. Continue flipping it around and doing the opposite end.

If there are no bubbles then force air through the engine by priming it. Prime the engine by pressing your finger over the exhaust pipe exit. Continue for a few seconds. 

You’ll see the petrol quickly making its way to the carburetor. 

Reason 5: Fuel Level too Low

We’re not making fun of you or your vision. It’s just that the gasoline level in the engine may be too low at times, causing the engine to stall. If you’ve recently filled the tank then there may be a leak somewhere.


Now this one is a no-brainer. If there are no leaks that are found, it’s time to fill. The answer as you probably know is to fill the tank.

Reason 6: Insufficient Fuel Tank Pressure

The reason the car is stalling is that enough fuel isn’t reaching the engine. The usual reason is that the pressure hose is loose. 


Change the pressure hose. The flow to and from the tank should then be checked. Examine the fuel tank cap’s seal. 

Examine the pressure line connecting the gasoline tank to the exhaust system. This aids in the feeding of fuel to the carburetor. If there is a pressure leak, the engine’s performance will be very erratic.

Remember to apply oil to your RC car’s shocks. So that they don’t deteriorate.

Still Stalling? Here’s How to Stop the Problem

Even after you completed our prior steps, the engine continues to stall. The previous methods were the usual causes and had easy solutions. However, this is a little more complicated. The Low-Speed Needle (LSN) is then too rich, and you will need to lean the engine. We’ve explained the subject in easy terms for your convenience.


Make changes to the fuel-air mixture entering the engine. Adding more oil to the fuel mixture is called lean.

The proper fuel mixture keeps the engine running at peak performance. The incorrect mixture can cause overheating and vapor lock. It can also cause excessive wear and stalling of the engine.

Also, there may be a problem with your pull-start. In that case, you can try to start your RC without using a pull start.

Wondering why the nitro engine keeps stalling when hot?

The fuel mixture is most likely too rich for the engine to manage. It causes the engine to overheat and stall. Then, with a few high-speed runs, fine-tune the HSN until you reach pure speed. Then, turn 1/8 of a turn counterclockwise to gently richen.

Tired of the Nitro RC? Here are Some Alternatives.

Have faced too many problems with your nitro engine. Thinking about getting a new RC Car. A possible solution is replacing the motor. Here are some recommendations:


Why does my nitro car stall at full throttle?

If you begin to slow down while driving at full power, you should lean on the upper HSN needle. Unwind it one full counterclockwise rotation. If the car will not idle at this point, you are too rich on the LSN bottom needle and have been tuning incorrectly.

A clogged air filter will deprive the engine of oxygen, causing it to die even when running at full power. The engine may idle normally, but it may not receive enough gasoline at higher RPMs. If you want to inspect or change your gasoline filter. Then, from the tank to the carburetor, trace the gasoline line to the filter.

How can I make my nitro RC faster?

If your engine is running at 20% nitro, you may boost top speed by increasing the nitro of your gasoline. As you raise the proportion of fuel, you may need to adjust the head shims under the heat sink head. The more shims you need to install, the higher the nitro concentration.

How does a nitro RC engine work?

RC engines, like diesel engines, use compression ignition. The engine lacks a spark plug that ignites the fuel at a precise moment. As a result, the fuel simply ignites when crushed or squeezed to a precise point. The compression ratio and glow plug control the actual ignition timing.

Bottom Line

Nitro Engine Stalls when Accelerating is a common problem that is faced by RC car enthusiasts. So, don’t feel disheartened when you face the issue. We’ve tried to present the topic in a simple manner. 

Have faced other kind of problems? Let us know in the comments below.