ORIGINAL: Dauntae
This might answer your question, I found it in another thread written by Geistware
2 strokes and 4 strokes generate the same amount of heat energy during combustion.
4 strokes have a hotter exhaust because you have cooling of the exhaust flow during the scavenging of the cylinder during the exhaust/intake timing of the two stroke. There is no scavenging or cooling of the exhaust in a 4 stroke. This enables the exhaust of the 4 stroke to be hotter.
Dauntae
i agree with the echaust explenation, but "2 strokes and 4 strokes generate the same amount of heat energy during combustion." is totally wrong.