Nitro powered radio controlled models offer an insane amount of speed and performance in an incredibly small package. The little two-stroke engines that propel these vehicles pump out a tremendous amount of power for their size, and spin at astronomical RPMs. The operating tolerances of these engines are very tight and are designed with extreme care for perfect fit and operation. Corrosion derived from moisture or other contaminants can rapidly break down an engine's ability to perform efficiently and reliably. Now, I know that we are not all big fans of taking things apart just to clean them. Although it's very tempting to just toss the vehicle up on a shelf after an all day bash session, it is not a very good idea. The times that you are allowed to do so will be quickly limited by the corrosion and gunk build-up that will form all around your chassis and engine components. Taking the time to perform these simple, yet effective maintenance procedures will keep your miniature monster in top condition, and ensure long life with less complications down the road.
Keeping it Clean
Keeping a nitro model (or any RC vehicle for that matter) clean is the first, and most important step of proper maintenance. Here are the tools and accessories needed for keeping your ride running and looking fresh.
Supplies
RC nitro cleaner
Air filter oil
After run oil
After-run Maintenance
When storing your nitro vehicle overnight it is necessary to perform the after-run maintenance procedure on the engine. After-run maintenance is critical for long life, and consistent tuning of your engine. The methanol in nitro fuel is a moisture magnet (hygroscopic), drawing in moisture from the air, thus inhibiting the precious metals inside the engine with rust and corrosion. Removing the raw, unburned fuel from the engine is very important. Also, fuel left inside the tank can turn bad in a short period of time, so removing all fuel from the fuel tank is a good idea as well.
The moisture absorbing properties of the methanol inside of the fuel can cause real havoc on your engine's connecting rod.
Starting the engine to burn off the left over fuel inside of the crankcase is a very important step in the after-run procedure. Corrosion can start immediately if raw fuel is left inside of the crankcase.
Overreving the engine is not the only way to damage the internal components of your mill. Lack of proper maintenance, and the usage of improper fuel can lead to the same results. These plugs were taken out of engines that were contaminated with corrosion.
After-run Procedure
Perform these after-run steps before storing the vehicle overnight.
1. Empty the fuel tank by drawing out the left over fuel with an empty fuel bottle. Do not place this fuel back into the can of fresh fuel. The old fuel must be properly disposed of. Give the bottle a squeeze before entering the tip into the fuel tank. This allows the bottle to draw in the raw fuel from the tank. Repeat this step until all fuel is in the bottle.
2. Try starting the engine. The engine should fire and run brifly (in the idle position), burning off left over fuel in the fuel line, and in the engine crankcase. When the engine has burned the last bit of fuel, the engine will idle up briefly, then stall.
Note - Look at the small gap between the slide mechanism and the inner edge of the inlet tract of the carburetor. This is a good starting point for the idle adjustment setting.
3. Clean the exterior of the engine case and carburetor by blasting the grease and dirt away with the denatured alcohol, or nitro cleaner. Use a small brush to aid in the removal of any stubborn particles that are difficult to break loose. Dry the engine case with compressed air.
Caution: Always wear safety glasses and gloves to prevent injury when handling hazardous chemicals, and using compressed air. Once the engine case is clean and dry, remove the glow plug and air filter from the engine.
Do not over-look the area between the cooling fins of the cylinder head. This is a very popular place for dirt and grime to hide. Excessive dirt between the fins, like this one here, can cause the engine to run very hot, making the engine difficult to tune.
4. Remove the air filter from the carburetor. Open the throttle fully and squirt a one second burst of WD-40 into the carburetor and also into the glow plug hole inside of the cooling head.
5. Remove the air filter element frm the filter housing. Clean the element and housing components with warm soapy water (dish washing liquid, such as Dawnâ„¢, works very well), and allow the pieces to dry completely.
Sqeeze the air filter base just below the housing and pull the base out from one side for easy removal.
Work your fingers into the filter element until clean.
Compressed air can be used to accelerate the drying process of the air filter components.
Once the filter element is dry, apply air filter oil, evenly around the entire element.
Do not squeeze out any oil from the element. Work the oil into the element with your fingers until there is an even color of oil throughout the entire element. Reinstall the filter element into the filter housing.
Note
It is recomended to clean the air filter after every hour of runtime with the engine (approx. one 500cc bottle of fuel). If the vehicle is operating in very dusty conditions, cleaning the air filter after every 30 minutes of runtime will be necessary to promote long engine life.
6. Attach the complete air filter assembly back onto the carburetor and secure it with a small zip-tie. Reinstall the glow plug [with glow plug wire (if necessary)] into the engine and reconnect the glow plug wire (where applicable). Now your engine is ready for another day of bashing and racing.
Fuel Filters
If you are using an inline fuel filter, it is very important to keep the filter clean and free flowing. Clogged fuel filters will cause tuning difficulty and poor engine performance. This means cleaning the filter on a regular basis. Cleaning the fuel filter at the same time ou clean the air filter should suffice. I recommend using a fuel filter that is made to be disassembled, or at least transparent, so that you can see the screen inside and determine whether or not it is completely clean.
The two-piece filters can typically be threaded apart with easy access to the finely meshed screen inside. Cleaning these types of fuel filters is easy. Remove the screen and clean all filter parts with denatured alcohol, forcing out all of the tiny particles and debris. Reassemble the filter and reattach to the fuel lines. Cleaning one-piece fuel filters is performed by back-flushing (forcing the cleaning solvent through the filter in the opposite direction of fuel flow) the fuel filter with pressurized denatured alcohol or nitro cleaner.
Chassis Maintenance
This truck is in dire need of a good cleaning. it's definitely a blast when we are in the process of making our trucks look like this one, but the fun will soon come to a halt if we do not develop good maintenance and cleaning habits.
Between running sessions it is a good idea to clean off the chassis with denatured alcohol, and wipe away the dirt a debris from the chassis. This keeps the collective build-up of dirt and crud from getting out of hand, and causing a huge cleaning task later. More importantly, it prevents the grime build-up from producing greater problems with the vehicle functioning incorrectly. Also, inspect the chassis and drivetrain for any broken or damaged components.
Start by spraying denatured alcohol onto the dirty areas breaking up and flushing away as much grit and grime as possible. Be careful not to get any alcohol onto the electronics. If the vehicle is so grimy that it is unavoidable, then remove the radio gear from the chassis before continuing further. Use a small brush to assist in the really bad areas.
Once the chassis and components are free from the grunge, dry off the vehicle with compressed air.
Keeping dirt and gunk from caking up around the drivetrain and suspension components will not only prevent complications, but it will also provide a better handling truck too.
Follow this quick checklist of procedures and visual inspections between running sessions.
Check for:
1. Loose or missing screws (especially engine mounting screws)
2. Cracked, bent, or damaged parts
3. Cut or loose wiring
4. Torn or kinked fuel lines
5. Fuel leakage (due to a cracked fuel tank)
6. Damaged or stripped drive gears
After cleaning the chassis and suspension, check over the chassis once more for loose screws and damaged parts. Engine screws are especially important. Always double check the mesh between the clutch bell and the spur gear before each run. Also, pick out any debris that may have found its way in-between the teeth of the gears. The vibration from the nitro engine, coupled with any rollovers or nasty wrecks, can loosen the these screws allowing the engine to shift. This causes the clutch bell to pull away from the spur gear losing proper gear mesh, thus wiping out all of the teeth on the spur gear.
Just a drop of medium compound thread locker on each of the engine mounting screws is all that is needed to help prevent the screws from loosening due to the vibration of the nitro engine.
Medium thread locking compound is beneficial when used on the engine screws to prevent the screws from backing out.
Other key items to check include:
Slipper tension and friction pegs - Make sure that the slipper adjustment is set correctly. A good starting point for the slipper on the Maxx trucks is 1/4 turn back from tight, and the N. Rustler can start around 1/2 turn from tight. Also, make a regular check on the friction pegs for wear. When the pegs wear down to the spur gear, it is time to replace the pegs with new ones.
Throttle linkage and set screw collars Make sure that the set screw collars are fastened securely to the linkage rods and that the rods themselves are not bent or binding.
Free suspension movement
The suspension arms must move freely to function properly and consistently. Remove the shocks from the suspension arms and make sure that the arms move freely up and down. If there is any binding, check the suspension pins. Bent suspension pins will cause binding and will need to be straightened or replaced.
Adjust pivot ball caps
On the Maxx trucks, you will also need to check the pivot balls for smooth action. Dirt can get trapped inside the hub carriers around the pivot balls causing tight movement. Loosen the pivot ball caps slightly and flush out the pivot ball housings with denatured alcohol to free things up. Once clean, readjust the caps so that the hub carriers pivot smoothly with minimal play.
Shock shafts
Check each shock shaft to make sure that they are not bent. A bent shock shaft should be replaced immediately to avoid permanent damage to the shock body and seals.
Wheel axles
Clear the axles of any loose debris, such as: grass, weeds or string that might have become wound up around them. Make sure that the axles spin freely.
Electronics
Open up the battery and receiver boxes to check for moisture and dirt. Receivers with balloons must be pulled out regularly to make sure that raw fuel or moisture has not found its way inside to cause damage. If the balloon is torn or has fuel residue inside of it, then it will need to replaced.
Fuel tubing
- Check both the fuel line and the pressure line for splits, cracks or tears. Replace the lines if needed.
Tyres
- Unglued sections of the tire like this one will allow dirt to collect inside of the tire. The accumulation of dirt and debris adds up to extra weight, and will throw the whole wheel out of balance reducing the life of your bearings. Check around the bead area of each tire to see if it has become separated from the rim. If so, clean the area as well as possible and reapply a small amount of super glue to secure the tire bead back to the rim.
Long Term Storage
1. Perform after-run procedure on engine. (This is extremely important for extended storage periods).
2. Clean chassis and suspension free from all dirt, grime and exhaust residue.
3. Remove all fuel from fuel lines and fuel tank. (Fuel will gel and clog the lines over a short period of time. If they are not cleaned out before storage, then they will need to be replaced before the next running session).
4. Remove all batteries from the receiver box and transmitter. (Batteries can vent, or basically explode, if left inside the vehicle or transmitter for a long period of time. This can ruin the transmitter and the receiver battery box if they are not removed for storage).
5. Remove all wheels and tires from the axles and store in a separate container. (Prevents flat spotting the tires and inserts).
6. If storing the vehicle in the garage or in a storage building, spray a light coat of WD-40 onto all of the metal components (including hardware) on the chassis. (This keeps rust and corrosion from forming on the any of the metal components).
If you follow the advice above your nitro vehicle will stay happy and healthy for a long time. Remember, the short time spent performing these maintenance and storage procedures will ensure many more hours of fun running your nitro powered vehicle in the future. Damage to the chassis or electronics due to neglect, or failure to provide proper maintenance to your vehicle will void any kind of warranty claim associated with the problem.