I have a 99 sportsman 500 with a 40 millimeter carburetor on it. With the four wheeler in neutral and I tried to give it gas it sputters and bogs down. As I take the lid and air filter off it’s somewhat straightens out. But as soon as I put the air filter on again, it starts to act up. The exhaust coming off of the thing. Took off the spark plug and it is black as the ace of spades. I completely rebuilt the carburator last year. Took apart the carburetor again last night and everything looks clean, this one has got me pretty stumped, any advice would be helpful
thanks

I have a 99 sportsman 500 with a 40 millimeter carburetor on it. With the four wheeler in neutral and I tried to give it gas it sputters and bogs down. As I take the lid and air filter off it’s somewhat straightens out. But as soon as I put the air filter on again, it starts to act up. The exhaust coming off of the thing. Took off the spark plug and it is black as the ace of spades. I completely rebuilt the carburator last year. Took apart the carburetor again last night and everything looks clean, this one has got me pretty stumped, any advice would be helpful
thanks