NEED HELP ASAP!!!

1996 timberwolf 250 2×4. New top end, new battery, fresh rebuilt carb, new starter, valves adjusted.
When I try to start it it drags and turns over very slowly. If I take the carb off and put my hand over the intake it turns over normal. i can get it started and it runs perfectly fine. It did this before the rebuild also. What am I missing here? Very frustrating.

NEED HELP ASAP!!!

1996 timberwolf 250 2×4. New top end, new battery, fresh rebuilt carb, new starter, valves adjusted.
When I try to start it it drags and turns over very slowly. If I take the carb off and put my hand over the intake it turns over normal. i can get it started and it runs perfectly fine. It did this before the rebuild also. What am I missing here? Very frustrating.