Things to Know About Nitro RC vehicles

Things to Know About Nitro RC vehicles

Posted by RC Masters on 18th Jan 2013

Are you the type of person who loves smoke and noise? 

Do you have a passion for extremely fast cars? 

Well, you might just be obsessed with nitro RC vehicles and must feel a bit stumped especially when you’re new to the nitro RC world. It’s not much of a fuss as long as you follow the necessary precautions and avoid the most common mistakes beginners make. Check out the following tips on starting a nitro powered engine.

  • Avoid pulling the pull starter if the engine is flooded - Much like the pull start mechanism on a lawnmower, a pull cord is attached to the nitro engine and you will have to pull the T-handle attached to the starter cord assembly to spin the flywheel and start the engine. But when the cord becomes difficult to pull, don’t force it. This just means that the engine is flooded, and pulling it will just snap the line. If this happens, remove the glow plug and turn the car upside down then pull the starter twice to remove excess fuel. Remember not to pull the pull start cord out more than 20 cm as this may bend the spring and/or snap the cord.
  • Never restrain the wheels – Always start the car with the wheels off the ground. Let the wheels spin freely and make sure the brake is off, otherwise it will result to overheating and will melt the nylon drive gears.
  • Ensure the brake is off before starting the car – Try pushing the car forward and if it gives a bit of resistance, chances are the brake is on. Make certain you turn off the brakes before starting the car. Failure to do so might cause the clutch to overheat and will melt the nylon drive gears.
  • Don’t replace the nylon gear with a metal gear – The nylon gear will provide a safety margin of 60 degrees since they melt at about 220 degrees Celsius while the aluminum clutch bell will break at 280 degrees. Metal on metal also wears out very quickly when not lubricated and lubricating gears often may wear it out even more as lubricants attract too much dust and dirt. The lighter the car, the quicker it is and metal gears are way heavier than nylon ones and it will most likely impede the car’s ability to accelerate.

You may be interested in getting a nitro RC vehicle and you certainly want to know how it works first and the basic setup involved in obtaining one. These following steps will help you prepare, start and break-in your nitro engine.

  • Charge glow igniter – This is mainly the first thing you need to do once you open up your starter kit. Without it, you will not be able to even start the car. After charging your igniter you should make sure the glow plug igniter is not left on the glow plug too long else it will burn out.
  • Install radio batteries – put 8 batteries into the transmitter and 4 into the receiver (nitro cars only) and make sure for rechargeable ones that they are fully charged before installing them. Once the batteries are in, first turn on the transmitter, then the receiver. If you ever turn on the receiver on the car first, it won't have a signal from the transmitter to follow, and may go out of control.
  • Fill the tank - Pour some fuel into the starter kit's fuel bottle. Fill up the fuel tank with nitro, and make sure all fuel lines are connected to their ports. Make sure you are using proper high quality Hobby fuel with correct nitro percentage (20 – 30% nitro), unless stated otherwise in the manual. One thing you have to remember is not to bend the fuel lid right back. This will result to bent spring in the lid and will not pressurize the fuel tank.
  • Install your air filter – Some models may already have the air filter readily installed. If not, just install yours onto the carburetor. It may come with a zip tie that you can use to secure it to the engine.
  • Standing your antenna up - Antennas are important in RC car setup. You will have to insert the wire first through the antenna mount of the car, and then right through the tube and finally the tube goes into the tube mount. But in case of longer wire, let the line hang freely and don’t cut it.
  • Turning on your transmitter first - Remember: transmitter always goes on first, and off last.
  • Check for proper operation of servos – While engine is not running you can check if steering, throttle and brake servos are working correctly with the use of the transmitter and receiver. RC servos are used to provide actuation for various mechanical systems such as the steering of a car. Ensure that the wheels of your vehicle are off the ground so it can spin freely if you want to test how the servos are operating. When you apply the throttle, it opens up the carburetor and when the brakes are applied, the carb is closed almost all the way, and the brakes are then engaged.
  • Checking the radio range - Make it a habit to always test your range before you drive your car and ensure you’re free from any radio interference particularly with the 27Mhz frequency that can be caused by power lines or 2-way radios that transmit on a similar frequency. To do a range check you can walk 5 meters away from the car with the models aerial fully extended and the transmitter aerial fully down. Turn on the radio system and check that all servos are working correctly. Do not attempt to drive your car if you notice any radio problems or interference and see to it that the batteries are strong and fully charged.
  • Prime the engine with fuel - This is simple, just put your finger over the exhaust port and pull the cord a few times until you see the fuel go through the line and into the carburetor. Once the fuel reaches the carb, stop or you will flood the engine. Cold engines require more priming than hot engines.
  • Starting a nitro engine – Don’t start your engine unless you have fully read and understood the directions. Assuming you’ve gone over everything and now that the engine is primed, it’s ready to run. Clip the igniter onto the glow plug and pull on the cord. Make sure you do short, quick pull.
  • Keep the engine running – The first time you start it, chances are it won’t stay running and you may not be able to run it like you want to. You have to break it in and set the mixture correctly to make the engine last longer. You can try turning the throttle trim dial on the transmitter to keep the engine revved up. If the engine stalls, you may have to adjust the idle and slightly raise it.
  • Proper engine break-in - Before you start to run the car as much as you want, it is very important (crucial, even) that you break in the engine. You may encounter stalling and inconsistent runs but these are all normal until you get to break in the engine and set the mixture. If you do it properly, it will help you achieve the highest possible performance and reliability.
  • Break-in procedures - Basically all you do is run the car at low speeds for a few tanks of gas. Keep in mind that the wheels should be off the ground and the brake must be off. Simply idle 3 tanks of fuel, allowing the engine to cool down between tanks. Remember to always check your car for loose nuts and bolts. After the first run, go over your car and make sure all the screws are tight, especially the engine bolts. You can try using a Locktite (like a soft glue) to help keep the nuts and bolts in place, since they tend to come loose due to vibration. After the third tank, check the gap between the metal clutch gear and the nylon drive gear. There should just be a really small gap that could allow 2 pieces of thin paper between the 2 gears. If the gap is bigger than what’s necessary, you may adjust by undoing the screws and sliding the engine closer. For your succeeding tanks, you can gradually increase how hard you run the engine. Soon enough you can do it however you want.
  • Break-in mixture settings – Most engines are pre-set with the default mixture settings from the factory. This should be good unless you would need to adjust the setting for different conditions. When you need to change the mixture settings, record the factory settings. Count and record the turns so you can wind them back to default.
  • Running the first tanks in the car – You may have broken in your engine at this point and hopefully you did it correctly using this guide. Try a smooth surface first on your first run and check the steering trim to make sure it’s properly adjusted.
  • Engine tuning - When it comes to RC vehicles, tuning is essential in order to achieve more speed or power. The overall performance of the engine greatly depends on how you tune the mixture. We have the rich and lean setting; both terms are used to describe the amount of fuel entering the carburetor. Lean means less fuel while rich means more. If you want to have a leaner setting, turn the carburetor needles clockwise, while counter-clockwise would help you achieve a richer setting. Make sure you’re not running too lean as this may damage your engine. Engine life should be operating around temperatures 104-115 degrees Celsius or 220-240 degrees Fahrenheit.
  • Fine tuning – This would mean adjusting slowly the low-speed mixture and idle screw. Note that if the engine splutters, it is too rich and when it tries to cut out, it has a lean setting. You would have to listen to the way the engine revs from idle to determine your current setting.
  • Installing the body clips - Putting on body clips on an RC car is easy. You just have to align the holes in the body with the body mounts. Then clip the pins on through the holes and you can pretty much adjust the height of the body by lowering the clips.
  • How to stop the engine – You can stop the engine by either blocking the air using your fingers or squeezing the fuel line to the carb.
  • After run maintenance - Make sure the fuel tank is empty. You can attempt to run the engine until all the extra fuel is burned up. Lastly, remove the glow plug and put a few drops of after run oil into the engine.

Now that you know most of the things that you need to learn when it comes to a nitro RC vehicle, you are all set. Remember to do the maintenance tip after every run. Love your model and it will let you have more fun in driving! Well, enjoy and it better make some smoke and noise.