The main jet is the smaller jet. There is 2 and the pilot is very easy to see. It sticks up a little higher than the main. If you remove the wrong one, The main is about a 1/4in long. The pilot is around 1in long. Depending on what you do to your quad you may want to move up a little on the pilot jet. A pipe will kill a little bottom end torque. But by moving up a size on the pilot it will restore and improve bottom end. I had my jets out today. Now I've done it a few times, but it only took about 20 minutes and I even replaced my needle. Just take your time and it won't be a problem.