is there a reason the 50 cc 2 stroke quads exhaust have no expansion immediately after the head like the bigger 2 stroke bikes?

 

Cause 3/4 " pipe is cheap and is fine for yard bikes designed for 6 yr old. Welded cone sections are expensive to make and even a stamped pipe costs more than 3/4" tube does. Honestly if the 50s ran like they should then there would be a lot less 40 lb 4 yr olds on 250 lb 90cc bikes.

 

Thanks, I was pretty sure that was the answer, but thought maybe the lil 50cc bikes couldn't take advantage of a collection chamber or maybe would somehow run worse.