The Cox .049 Engine is a 2-stroke internal combustion glow plug engine.These engines use a glow plug to heat the fuel/air within the cylinder to start. Once running it is disconnected and operates in the same manner as a diesel engine.
image/text credit: Imaginative Guy
The self ignition is due to the heat produced from the compression of the air/fuel mix, and the catalytic reaction of the platinum element in the glow plug and the methanol in the fuel and does not depend in any way upon the continued use of the battery.Fuel intake to the engine is controlled by a simple needle valve and venturi system.
Fuel/air mixture intake to the crankcase is controlled via a reed valve or rotary valve depending on the engine design.In a reed valve engine the valve is drawn open by suction as the piston moves upward on the compression stroke.
As the piston moves down on the power stoke, the pressure in the crankcase causes the reed valve to close. The fuel air mixture in the crankcase is then forced past the piston via the transfer/bypass ports in the cylinder.Millions of engines were produced and they became the most common 1/2A Class 0.049 cubic inch engine in the world and probably still are today.via(wikipedia)