I was tired of cleaning my old carb so I bought a new one. Quad has more power now but bogs out between 1/4 and 3/4 throttle, will also back fire. Idles fine and runs at full throttle. I have a also bought a Dyno Jet main jet for it. Used the size it says for under 3000 ft. with an after market exhaust. I have the adjustment screws set at 3 and 2, needles are both set at 5 of 5. What should I be changing?