There are both advantages and disadvantages associated with gas/nitro-powered remote control (RC) vehicles. Because they run on fuel, you’ll typically get longer “run time” when compared to battery-powered vehicles. They also deliver morepower and faster speeds, which is a huge benefit in itself. However, one of the downsides to fuel-based RC helicopters, cars, trucks and other vehicles, is the buildup of gunk in the engine.
When a thick sludge begins to accumulate inside an RC engine, it’s said to be “gummed up.” This phenomenon is the result of excess fuel evaporating, leaving behind a thick layer of sludge-like oil. Gummed-up engines are far more common when the RC vehicle has been sitting idle or stored for long periods of time. If you placed your RC helicopter in storage, left it for a year or so, and then took it back out, it may not start due to the fact that the engine is gummed up.
The first step in cleaning a gummed-up engine is to flush any remaining fuel from both the tank and engine. You can refer to your RC vehicle’s owner’s manual for more information, but you should be able to either drain it from the bottom or flip the vehicle upside down. Be sure to store the excess fuel in a proper container, and do not attempt to throw it away. Fuel is toxic to the environment and must be properly disposed of at a disposal facility.
There are several different ways to clean a gummed-up RC engine, and if you asked ten different hobbyists what the best way is, you would probably get ten different answers. With that said, I’ve found one of the easiest and most effective ways is to disassemble the engine and soak the parts in alcohol overnight. Some people prefer to soak their engine parts in petrol, but alcohol is cheaper and works just as well if not better.
Denatured alcohol is the best kind to use, and will not cause any harm to plastic parts.
After allowing your engine parts to soak for at least one full night, remove them from the alcohol and lay them out on some paper towels to dry. Don’t worry if the engine parts aren’t completely clean, because we aren’t finished just yet.
Once they are dry, spray the parts with a generous amount of WD-40 or similar silicone-based lubricant spray, such as the Nitro Kleen – this cleaner is safe on plastic parts and removes dirt, oil residue, grease, and grime. It also comes with a trigger and spray tube for getting into smaller areas.
After spraying, scrub your engine parts with an old toothbrush. This should make easy work of even the dirtiest, gummiest RC engines. Let the parts dry once again, at which point you can reassemble the vehicle.
To prevent future buildups of fuel and oil gunk, it’s recommended that you give your engine a thorough cleaning once every 1-2 months.