that's odd because i had to richen my engine to get it to run right. going from the stock
.70 jet to a .74 jet got rid of my top end bog big time, I even picked up about 3 mph by re-jetting it richer.
no, i don;t have an air leak, and my plug is a nice tan color now.
with the .70 jet my plug was a silvery color, which indicates that it's too lean.
I live in the midwest U.S.A. and I did this when the outside air temp was in the mid 80's.
my engine has a long pipe with a modified stock muffler (no expansion chamber) and a velocity stack with a high flow k&n style filter inside it.
normally if a 2 stroke is too rich you will experience 4 stroking on the top end, which is totally different than a bog.