Couple Engine Concerns!

also, it will start without the choke, but if i put the choke on, the engine shuts off. is it too rich?
and i took off the airbox lid and it sounds kinda loud. i figure this is normal, just want to make sure. any help is great
 
i run premium and yamalube at 32:1 but i finally got it to run right. i made the needle a little richer too. and with the 270 main and ran with the airbox lid off. it runs beautiful. it idles smooth and the powerband is just right! and it has a lot better throttle response and when i gun it, the front comes up! i did the spark plug test and its a tanish brown. almost like a pancake type color. thanks guys for all of your help