hello. I have 2 Honda Recon 250es bikes doing the exact same thing. the bike will not run(spits- bogs - no power) unless the choke is a little less than half way on. this to me would indicate a vaucum leak because you are blocking air flow when the choke is applied. I have checked all of my vaucun lines, removed the carb , cleaned and checked the bowl for trash and cleaned , and checked all mounting bolts. Is there a chance that the boot connecting the carb to the head is cracked or is therr possibly something i am overlooking. please help.