ill just go from the start here, i bought that 95zx6r used, motor was having few probs, had 23000 miles on it, so i went out and got me another motor, this is is good has 13,000 miles on it, i spent the weekend putting it in, all done now, took it for a test run tonight, revs fine, has power in first gear, but when i get to the end of 2nd gear, it doesnt want to go any higher, it just looses power, i go back down to first and its good, so any ideas? the carbs were jetted to the old motor, do they have to be redone? or could it be the spark plugs??,, one more question, how loud should the stock airbox be? after this motor it seem to be a bit louder

 

It's possible the jetting is off on the top-end. Does the engine rev to redline in 2nd gear?Short shifting to 3rd and try it. What was your original problem that you swapped engines?