Nitro RC Car Maintenance: Your After-Run Routine

A well-maintained nitro RC car starts on the first pull, holds its tune better and its engine lasts much longer. The trouble is that nitro fuel leaves residue and moisture in the engine, and these cars usually run on dirt. That’s why the after-session routine matters more than it does on an electric car. Here’s the one we recommend.

1. Empty the tank and the carburetor

When you’re done, empty whatever fuel is left in the tank with your fuel bottle. Then start the engine and let it idle until it stops on its own: this burns off the fuel left in the lines and the carburetor. Old fuel breaks down and makes the next start harder.

2. Clean the car

Take the body off and remove dust and dirt with a brush and compressed air. The engine and the underside of the chassis collect a mix of oil and dust: clean it off with a cleaner made for nitro engines or with isopropyl alcohol and a brush, without soaking the electronics. You’ll find more on cleaning the chassis in how to clean an RC car.

3. Look after the air filter

The filter is the only thing standing between the engine and the dust. If dirt gets in, it scores the piston and sleeve within minutes.

1. Remove the filter and take out the foam.
2. Wash it with warm soapy water or a filter cleaner, and let it dry completely.
3. Soak the foam with air filter oil and squeeze out the excess.
4. Refit it and check that it sits snugly on the carburetor with no gaps.

Many drivers carry a spare, pre-oiled filter to swap at the track. Look for RC air filter oil and a spare nitro air filter.

4. Protect the engine with after-run oil

Nitro fuel contains methanol, which attracts moisture and rusts the bearing, crankshaft and connecting rod if the car sits for days. To prevent it:

1. With the engine cold, remove the glow plug.
2. Put a few drops of after-run oil into the combustion chamber and the carburetor.
3. Turn the engine over with the starter for a few seconds to spread it.
4. Reinstall the glow plug.

A bottle of nitro engine after-run oil lasts a long time and is one of the purchases that does the most to extend engine life.

5. Check the glow plug

A bad glow plug is the most common reason a nitro won’t start. With the glow plug igniter attached, the element should glow bright red. If it’s broken, bent or glows weakly, replace it. Always carry a spare: look for nitro RC glow plugs of the type your engine’s manufacturer specifies.

6. Clutch, drivetrain and hardware

• Clutch shoes and bell: no excessive wear, so the car doesn’t creep forward at idle.
• Pinion and spur gear mesh: there should be minimal backlash.
• Engine and engine mount screws: vibration loosens them. Use thread locker on any that go into metal.
• Bearings: spin them by hand; if they’re noisy or feel notchy, clean or replace them.

7. Tuning and temperature

If the engine behaves differently after a cleaning, check the tune. An engine that’s too lean runs too hot and gets damaged; one that’s too rich smokes a lot and lacks power. We cover the adjustments in how to tune a nitro RC engine.

8. Storage

If you’re putting the car away for several weeks: empty tank, after-run applied, clean and oiled filter, receiver battery half charged or disconnected, and the car somewhere dry. Before you run it again, check the glow plug and the filter.

With this routine, starting your nitro will be much easier next time. Still deciding whether nitro is for you? Read our guide to nitro and gas RC cars.