engine problems! please help

So i tried the carb mod where you drill a hole to get air past the jet from the float bowl, and that made my engine lose power and only idle with the choke on, so i put my new spare carb on but the engine still doesn't run well under power and will stall after idling for a little while even if the throttle cable is adjusted so that its idling at a high rpm... im not sure if my gas mixture is right... could that make this happen? also i changed my sprocket to a 38 but it was running fine b4 i changed the carbs around.

"if it isn't broken and you mess with it long enough, it will be" really applies here

yea, i did a pretty good job i think, i didn't take the new one apart. i'll check the head bolts but im sure they're fine...

well between a better mix of gas, a new carb, and a little ilde adjustment im on my way again! (not for long though, my crappy bike sprocket set up had me pushing and pedalling back up a mountain) i'll be posting a video of the trip sometime soon