So I'm still working on my 89 trail boss 250. I've replace gas line and filter, new spark plug, new coil, and rebuilt carb. It was running until I had to adjust the float arms cause it was flooding itself. I got it running again but the idle was really high so I adjusted the idle screw some. Now when I run it if I run the throttle some it bogs down and dies, but when I put the choke on its ok but after a few seconds of that it starts to die cause of no fuel so I turn the choke back off and it runs fine again until I try and throttle up then it bogs again...what the crap???

 

Check the carb again! Either starving for fuel(jets stopped up) or float level/needle and seat problem not allowing enough fuel. Running on choke only is usually a sign of fuel starvation in the carb. OPT