You are most likely talking about the carburetor on older engines.
Steam engines have been replaced by electric motors for most applications.
An automatic choke is connected to the carburetor on small engines. To get a new automatic choke, a new carburetor will need to be purchased. It is easier to install a manual choke and less costly. Kits for this are sold at most automotive repair stores.
Most helicopters use gas turbine engines, which wouldn't have a carburetor. There are still some manufactured which use reciprocating piston engines, though, and many of those do use carburetors (one example is the Robinson helicopters, which are powered by a Textron-Lycoming 0-320 motor).
Fuel Injection. This is controlled by a computer which squirts just the right amount of fuel into the cylinders depending upon what amount is required (more in going faster or uphill or carrying a heavy load). That not only prevents wasted fuel but also helps the engine to run more cleanly, If a catalyst filter is fitted too, this removes or changes the nasty gases coming from the exhaust pipe into otherwise fresh air.
Most steam engines except those used on tourist railroads have been replaced with the more efficient steam turbine engines.
It's not necessary if you have fuel injection. Any gas engine which does not have fuel injection, like most small equipment engines, uses a carburetor. The carburetor releases the fuel as a mist into air being drawn into the engine. That gets fuel and oxygen into the combustion chamber in a highly combustible condition.
Most common camshaft used in today's car engines is DOHC (Dual Over Head Camshaft). Most of the manufacturers in the world are using this cam shaft in their cars, as it is most practical and has a four stroke cycle and gives more breathing space to the engine.
In most cases, you can locate the carburetor screws in the front of the carburetor. Sometimes you have to remove the air gilter to get to to the carburetor.
A carburetor diagram for your 1986 Ford, can be obtained from most Ford dealerships. The carburetor diagram can also be found at most auto-parts stores.
Most of these engines had the fuel pump bolted to the lower left side of the engine block.They were a mechanical driven pump.Just follow the fuel line back from the carburetor.
they are 4 stroke engines...