Engine Shut Off

The topic of how to shut down a nitro motor provokes a large amount of debate. Most of the debate is not necessary however, as most of the common methods are just fine. However, to avoid any confusion, I’ll run through the common methods below.

Pinching the fuel line

This method works very well, provided the motor is properly tuned. Where you pinch the line isn’t important, as the pinch prevents the motor from obtaining any more fuel period. It isn’t going to use what’s between your finger and the carburetor.

You should avoid using any throttle during the shut off however. Since you are starving the motor of fuel, it will run lean for a moment. This isn’t an issue if the engine is simply idling. The engine may speed it’s idle up momentarily, but will shut down within a few seconds.

Stopping the flywheel

This is a popular method, especially on flat chassis vehicles like 1/8 scale buggies. All you simply do is apply pressure to the engine’s flywheel to stop it from turning. This will shut off the engine as well.

There’s nothing wrong with this method, although I’d recommend using the tip of your shoe. While some people use their fingers to stop the flywheel, it’s also a good way to get a nasty pinch.

Plugging the exhaust

This method consists of using something to plug up the exhaust stinger on the vehicle. Without a way to expel the spend gases, the motor will shut down. This method is recommended by many manufacturers, and is safe as well. There is a small possibility of flooding if you are using a new motor that hasn’t had a lot of fuel run through it. However that very minor chance is often overplayed in most instances. I often use this method myself.

Plugging the air filter

This method, and that of removing the filter and blocking the carburetor, should be avoided. There is a high potential of debris getting into the engine when messing with a dirty air filter.

Final thoughts

Most of the methods above will work just fine. However, for the last tank of the day, I recommend allowing the vehicle to run all its fuel out. This helps to ensure that all of the fuel is completely out of the fuel lines and tank.

If you need to, because of a broken part, dump out the fuel so that the engine runs out of fuel quicker. You should also avoid using any throttle during this procedure as well, because once again you are starving the motor of fuel as you would if you had pinched the fuel line.