How To - Clean a gummed engine
Article #542615

Post Storage Engine Preparation

Engines stored for a long period of time may require minor preparation before being started for the first time in several months. The after run procedure is intended to help minimize the effects of long term storage, but sometimes engines are stored with fuel in the vehicle or without proper preparation for its hibernation. Fuel left in a vehicle over a period of time will evaporate leaving a thick sludge of oil in the tank, carburetor, and engine- resulting in a no-start gummy mess when you return to use the vehicle.

  • First, it will be required to flush out the old fuel from the tank and engine. Begin by draining any remaining fuel from the tank, and thoroughly flushing the tank clean with fresh nitro fuel.

The fuel remaining in the engine for a long period of time may gum the carburetor, main engine bearings, and piston assembly- preventing the engine from being able to rotate or draw fuel. Depending on the condition of the engine or the extent of the damage, the engine may need to be removed and cleaned out if it will not turn over.

The engine should rotate quickly when the EZ start system is used to turn it over. If the engine is gummed up and you cannot turn it over easily by hand, remove the engine to clean it out.

If this still does not allow the free flow of fuel, this link overs how to clean or completely rebuild a TRX racing carburetor for the 2.5 and 3.3 series engines. It may also be necessary to replace old fuel lines with new pressure and pickup lines to allow unrestricted fuel flow from the tank to the engine.

Consider also the age of the fuel and how long it has been stored. Once opened, a container of nitro fuel should be used within 3-4 months depending on how it was stored. Be sure to start your season off with a fresh container of fuel for best engine performance. Once the engine is given a clean bill of health and the vehicle is ready to be fired up, remember to tune the engine for performance and clean your air filter after every hour of run-time. Always perform the after run procedure and remember to clean the air filter after every hour of operation in order to maximize the performance and lifespan of your engine.

Recommended Reading:

Full rebuild of the TRX Racing Engine
Tuning the TRX Racing Engine
Air Filter Maintenance
Maintaining and storing your Traxxas vehicle