Gee, being a simpleton, I've always thought of 4 stroke engine cycle as
SUCK - SQUEEZE - BANG - WHOOSH and 2 stroke as
BANG - WHOOSH - BANG - WHOOSH 
The Cox's are in the latter category. Model plane fuel keeps the element glowing hot in the glow plug. The rest is magic.

Enough theory, it's time to fly. [8D]