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Why Does A Nitro RC Car Stall? (Nitro RC FAQ)

Nitro RC cars are extremely fun to race and use with your friends. Even though they are a lot of fun to race and bash with, many people want to know why their Nitro RC car stall. 

The main reason for stalling is that the air filter is dirty and needs to be cleaned. This can happen from general wear and tear or from rough play. The only way to fix a stalled Nitro RC car is to clean the air filter.

If you have a Nitro RC car, then you need to know other reasons why it will stall. The most common reasons for stalls are: dirt in the engine, overheat, incorrect fuel mixture or running out of fuel during long races.

If the car stalls, then there are only a few things that you need to do to fix it. First, you will need to check for any broken parts that might be the reason for the stall. Next, you need to clean off the dirt in the engine with a toothbrush or small screwdriver. Lastly, if nothing works and it is overheated from running out of fuel; then you might have to replace your motor.

There are a few items you can buy from your local hobby shop or online that will help clean your Nitro RC cars. There are also places that sell special filters for Nitro RC cars but they will cost more money as compared to the regular filters.

Nitro RC cars are not toys, they are tools. If you do not take care of them, then they will break and you will need to spend more money to fix them.

If you are using a Nitro RC car for the first time, then you might not know what is normal. There are a lot of things that can cause your Nitro car to make noise; these noises are okay and should be expected. 

If it sounds like something is wrong, then it probably is. Inside the engine should be a ball bearing, but if this bearing gets mixed with the dirt particles in the engine and clogs the filter; then your car will stall when there is an increase of fuel or air flow through the engine.

To see the most popular nitro RC cars on the market currently you can click here. 

Why does my Nitro RC car stall when I give it gas?

When running a Nitro RC car, sometimes the driver will get into a situation where the car will not go when he gives it full throttle. This happens because nitro fuel ignites so fast that as soon as the motor spins up, it already has too much fuel in the combustion chamber and it stalls. The motor is spinning, but there’s no air-fuel mixture there to ignite.

There are two reasons this can happen; they are:

1. The fuel-to-air ratio is too rich or too lean (too much or too little fuel compared to air).

2. The timing is too fast or too slow.

A rich mixture is one that has too much fuel in the cylinder; instead of air entering the combustion chamber and mixing with the fuel, there is a huge amount of fuel. This is when you get white smoke coming out of the exhaust pipe.

A lean mixture is when you have too little air in the combustion chamber and not enough fuel. The engine tries to pull more air into the combustion chamber because there isn’t enough fuel to meet all of the cylinders’ demands. As a result, a lot of unburnt hydrocarbons will be left over in the exhaust stack, especially if you are running nitro on an aluminum motor. or too slow.

When the fuel-to-air ratio is too rich, you can smell the unburned fuel that’s coming out the back of your motor. This smells like raw fuel or a car running too rich.

When the mixture is too lean, you can smell a burnt paper kind of smell. This is from carbon and oil that’s being burned. If there’s enough oil in the combustion chamber it will probably blow a hole through your piston head gasket and kill your engine.

The timing being too fast or too slow are problems caused by the linkage between the motor’s crankshaft (the main rotating part) and its piston. The timing on these types of engines is measured in degrees and can be changed manually or by a module in the car that controls the throttle, valves, compression ratio, and much more 

How long do Nitro RC engines last?

The biggest factor in the engine’s life expectancy is the quality of the fuel you use and how much maintenance you give your engine. The second largest factor is the way you drive your car and how hard you break it in after a rebuild.

Let’s talk about the first factor, fuel quality. Just like in any car, a Nitro RC engine needs fuel to run – with gasoline being an exception which doesn’t need any fuel to run, but we’re not concerned with gasoline engines here – nitro engines need nitro and oil to lubricate them properly and get them started.

The problem with nitro for most people is the “nitro stink” – this is the stench a nitro engine emits when started in the cold weather. Once started, the stench usually doesn’t last very long.

If you’re not used to building or servicing a Nitro RC engine, be sure to use an aftermarket “smell-proof” oil such as “Kawasaki Oil Smell Proof Lubricant”. Just put it in the crankcase and it will keep any smell and grease from getting back into your motor.

The next biggest factor in the life expectancy of your engine is how often you drive your car and how hard you break it in. If you’ve never broken in a new engine, put at least 1000 miles on it before running the motor on a race track or putting it on the nitro car.

If you’re just looking for a fun car or even if you’re a serious racer, the life expectancy of your nitro engine will be determined by how much you break in the motor and how often you run your car.

This is where brand comes into play. Most of the major Nitro RC manufacturers like HPI, Associated, Losi and Traxxas make quality engines that can last thousands of miles under good care. Of course there are always exceptions to every rule so be sure to read reviews from other customers to make sure you buy an engine with good performance records.

On average though, the life of your Nitro RC engine is around 30 years if it is taken care of, and not abused. 

Does RC Nitro fuel go bad?

The use of Nitro-methane and Nitro-iglo fuel in RC cars and trucks by no means guarantees that it will run forever. Both fuel types have a shelf life. Once it is opened, the fuel loses its useful life. Fuel starts to evaporate and change its chemical makeup after being exposed to air for a long period of time, which can result in the engine not only not operating as well, but also not running at all. It’s important to never keep fuel containers sealed when they are not in use. 

It’s also important to keep the lid tightly sealed when it is in use. Nitro-methane has an indefinite shelf life, but once opened, it should be kept in a cool area and used within 6 months. 

It’s also better to keep the fuel containers full. If you would rather not see frozen fuel in your machine during the off season, then store it outside and out of the sun. It’s also good practice to use paint thinner or other small engine cleaners to dissolve old fuel before draining your tank, and let it run for several minutes after you drain it completely to remove any remaining contaminants.

Can you use nitro and gasoline in your RC car?

No. Both fuel types are incompatible with each other. It will clog up your carburetor, and the ethanol content of gasoline will cause the nitro to break down much quicker, causing the engine to not run properly.

What happens if you use the wrong fuel in an RC engine?

The engine may not run at all. However, it could start up with a primer for a few seconds before dying again and leaking fuel.

Are there any other tips for maintaining RC nitro engines?

Keep your engine tuned up using a fresh glow plug and proper oil/gas mix. It’s important to clean out the engine after each run as well. This way, you will avoid having debris in the engine that could cause a fire. It’s also safe to take a small wire brush and clean out any excess fuel left in the tank that could cause spontaneous combustion.

What happens when an RC engine fails?

There are two main reasons for failure, overheating and running lean from not enough fuel or bad timing on the part of a driver. Most engines will start to vibrate if they are starting to run too hot. Pull over quickly and let it cool down. If your engine normally runs well but now it is not running right, then go through a checklist of possible problems. This will probably help you diagnose the problem.

If you own an engine that is homemade, be sure to use good quality fuel such as nitromethane or nitro-iglo fuel whenever possible. Extending the life of a homemade engine by using high quality fuel can greatly reduce repairs and prevent damage from occurring in the first place. You will also want to pay attention to what you’re doing when performing maintenance on it. It’s easy for things to go wrong when modifying or rebuilding engines, so make sure you are careful with all of the materials involved and not get yourself into any dangerous situations.

How do I know if my Nitro RC is running bad?

The most basic way to find out how well your Nitro RC car is running is to use a fuel pressure gauge (you can pick one up at your local hobby store). The gauges are about $10 and will work on just about any nitro vehicle. All you have to do is to hook it up to the fuel line after the tank, run the car for a while to see what the initial pressure reading is, and then get back in your car and head out on the track. 

After running a few laps check your gauge again and you’ll be able to tell if you’re losing pressure or not. If you are losing pressure, then that is an indication that you have either a bad tank of fuel or that something isn’t set right with your power system. In most cases, if you are losing pressure then you probably have a bad glow plug or venturi.

Another way to tell if your Nitro RC car is running right is to use a timing light. (You can pick one of these up at the same hobby store as the fuel pressure gauge). With these lights they will help you determine if your engine is losing power due to having either one or two hot plugs misfiring and the like. For instance, in the case of having a hot plug misfire it will show up on your timing light as being off 100 degrees. 

The part that you can adjust is the idle screw on the engine. Usually when you are racing these types of cars you want to set it at about a quarter turn out from all the way in. The reason for this is that if your car is a little bit lean, then by turning those screws out a bit it will make your engine run more rich and hopefully that will correct the problem.


Nitro RC racing is a fun way to spend time and have some great memories. It’s a great way to make new friends, learn about new skills, and have some good laughs. And you can even make a few extra bucks on the side by selling your parts from different cars you’ve worked on. 

If you are interested in getting into Nitro RC motorsports then simply get yourself a good engine kit to start out with and it will give you something to work on your garage with. As long as you are careful and take care of your parts, then you will be in for a great time.