It acts like you have it half throttle when your winding it out. Its running but acts like you got it half throttle? If your rolling in like 2nd gear and hit it it lugs for a sec then takes off?

I put a new set of plugs in it still the same. I'm sure its in the carbs. But not sure what to do. Anyone else had probs like this?

 

running rich maybe?

 

try switching the 2 carb slides out with each other, had the same problem once when had both carbs apart at same time and got slides accidently switched, one is for the choke carb only, maybe thats it, sounds like the same symptom that I had one time at least.