Motorcycle Repair: Sputtering and popping, pilot jet, fuel mix

Question
I own a 1986 Honda CB450,I'm converting it into a bobber, the problem I'm having with it is that at half and full throttle it sputters and pops alot. I took the original mufflers off and also installed K&N air filters, I also rebuilt and cleaned the carbs and sync them, this problem is quite annoying, it only does this in gear,very strange I think, can you help me? thanks

Answer
It sounds like you are still having a fuel problem. Think of the engine as a pump.You have increases the air intake and you have unrestricted the exhaust. More air is passing through the pump but the fuel mix has not increased with the air flow. You may have to go up 2 sizes on tha pilot jet and lower the clip on the slide needle.There is usually 5 grooves in the slide needle,try moving the circlip down to the 4th groove from the top or 2nd groove from the bottom. Next thing is are you running stock main jets if so do a little research. Some jet companies offer jets in incriments 5 some in half sizes. For example only (stock main jet 148) go up to 153 or 155 set float level by turning carb side ways with the float needle and hinge up let the float hang down freely the tip slightly so float presses down on needle. Run float parallel to base of carb. If you turn float to the top with the carb upside down you will get a false reading.Jetting may take a few tries to get it spot on but this may get you close.The jetting can vary a little depending on temperature and humidity and altitude.