Engines used to drive portable pumps and compressors shall be equipped with __________.

Engines utilized to drive portable pumps and compressors need to be equipped with exhaust system spark arresters for critical safety reasons. Spark arresters are devices designed to prevent sparks produced by the engine's exhaust from igniting combustible materials in the surrounding environment. This is particularly important in applications where the engine operates in outdoor or industrial settings where flammable gases, vapors, or dust may be present.

Having a spark arrester helps to mitigate the risk of fire, thus adhering to safety regulations while also protecting both personnel and property. It is vital for engines operating on combustible fuels, like propane, to have this safeguard to promote safe operation during situations where fires could be devastating.

The other choices, while potentially beneficial in their own contexts, do not address the specific safety needs tied directly to the operation of engines in environments where ignition risks are present. High-efficiency filters might improve air quality and engine performance, strong frames could refer to physical durability but do not directly impact safety concerning fire hazards, and remote control systems, while enhancing operational convenience and safety, are not universally required for the proper and safe operation of portable engines and pumps.