Q. Why generators have two inlets and exhaust valves while 2 stroke engine only have one valve?

Answer 1 Answers
Enrico Mercado

Answer: Because the scavenging/charging air system of the 2-stroke engine and 4-stroke engine are different.

A 2-stroke engine has scavenging ports in which the scavenging air passes to it when the piston reaches the bottom dead center. This air will also expel exhaust gas in the combustion chamber through its "Exhaust valve" (the one valve you said).

A 4-stroke engine has 4 valves (2 each for exhaust and intake), again this is a matter of charging of boost air and expulsion of exhaust gas in the combustion chamber, wherein 2 intake valves will open during intake stroke to introduce charging air to the combustion chamber and 2 exhaust valves will open during exhaust stroke.

I hope this helps.