Well it runs, so we can rule out a pile of things.
I'd pull those reeds out, and lookie see.
Take your exhaust pipe off and look in at your piston/rings, if there are blow by marks, pop the top end off, never hurts to redo it.
What are your compression readings??? Should be like 75 lbs first kick, 150 final, (Full throttle, spark plug grounded against something.
When was the last time it was rerung???
While I had the reeds off, pop your carb. I'd check the float height, spray some of that majical brake clean through all your jet circuits to make sure it's all clean and shiny.
How about the air filter??
Good luck and take your time.
Joe
Does it hurt?? Why yes it hurts! Do you think my leg always faced that way??