I have seen a number of discussions that showcase stories of someone who didn’t think they needed to break in the engine before bashing their nitro RC car. Wrong!
Those people couldn’t be more mistaken. It literally only takes a couple hours and five tanks of gas, depending on your specific nitro engine and brand. Real car gasoline engines must be broken in, so why would anyone think a nitro engine would be different?
In this guide, we're going to share with you a proper way to break-in your nitro engine.
For starters, you are going to want a rather large, clean area for the initial break in procedure. The last things you want are dust particles, weeds, rocks, and whatever else finding their way into your new nitro engine, especially since the body will be off for the break in process. Removing the body ensures the engine will get proper cooling.
Also, you may want to pick up a couple extra glow plugs or, at the very least, have a nice wire brush handy during the break in. The reason for this is that as you make adjustments, the glow plug will likely foul. This is completely normal and nothing to be concerned about unless you only have one glow plug around.
Always turn on the controller first!
Never, ever turn on your RC car, whether it be battery or nitro, without the controller being on. Outside frequencies might interfere, and the servos can go crazy. If you get into the safe practice of always turning on the controller and then the car, you’ll have one less thing to worry about.
Check your servos!
Once the car is on but before the engine is fired up, test the steering and throttle controls to ensure they won’t go haywire when you begin the break in procedure. The wheels should turn easily left and right, and the throttle should open up the carburetor all the way when pulled to the rear of the controller.
Break in your engine over five tanks of fuel
This is the part that I imagine new nitro users hate. All that time! I know, you just want to take your cool new car to the street and bash the heck out of it, but you’ll ruin it that way, plain and simple. Spend the afternoon doing it right; you’ll thank yourself later, and so will your pocketbook.
Keep in mind the general procedures listed below are just that: General. When it’s time to break in your RC nitro engine, search the Internet for your specific car or read the instructions (I know, I know, nobody does that). This article also assumes you can get the thing started in the first place.
Slowly, slowly, pull the throttle back to about a quarter of the way, leave it there for two to three seconds, then let off. In this stage, you are looking for mild to moderate blue smoke coming from the RC car’s exhaust, which means things are good and the engine is being lubricated. If there is no smoke after a few two-second quarter-throttle blips, richen the mixture a tad at the carburetor. Once you achieve a decent smoke, do two-second quarter-throttle blips for the entire tank. Yes, the whole thing. Don’t let it run out of gas, though, or you’ll foul the plug. Keep your eye on the tank and when it’s almost empty, kill the nitro engine by pinching the fuel line with your fingers. Do this for every step below, too.
It’s the same thing here, folks, only we are going to slowly move the throttle halfway for two seconds, then let it off. Always accelerate smoothly instead of jerking the throttle so that everything continues to work properly inside the nitro RC engine. It’s not time for stunts just yet there, Speed Racer.
Here we’ll be moving slowly and smoothly to half throttle for three or four seconds, as opposed to only two, and then braking. At this point, the engine’s idle might start speeding up, so it may be necessary to turn it down a tad. If the car wants to take off by itself at an idle, it’s too high.
Now we’re going for it! On this tank, we will smoothly accelerate to full throttle for three seconds, and then backing off using its brakes. It is important to be sure not to jerk the throttle at any time, because you do not want the car doing wheelies or skidding around. This is straight-line acceleration from idle to WOT (wide open throttle) for three seconds, and then back to idle again. Yes, for the entire tank. We are almost there!
Tank Five – You made it!
On the last tank of break in, accelerate to full throttle more quickly and hold for three seconds before backing it off. The goal here, again, is not to make the car flip or do wheelies. You should travel from idle to WOT in about three seconds. Hold it on the floor for another three seconds, then back it off. If the front wheels of the RC car are leaving the ground, you are accelerating too quickly.
Once that last tank is empty, your nitro RC car is ready to roll! Now you can safely bash it with your buddies or jump it or make it do wheelies and spinouts, because the engine has been properly broken in and is ready to rock. Slap the body on and go have fun!
If you skip this five-tank break in and just drive the car like a madman first thing, I guarantee you the engine won’t last more than a few hours. That’s an expensive woopsie, especially considering that these engines often last many, many years once they are properly broken in and maintained.
Don’t be that guy; break the darned thing in.