I am trying to fine tune my carb on my xr650l. It was running way to rich. I have since down sized all jets, and have slowly been bringing jet size up and backing out the needle. I have been checking my plug every couple hundred miles, and adjusting accordingly. It runs great, but does have minor pop in the 2-3 gear decel. Plug is not browning enough, so its needs a little more gas. I have two clicks left to back out the needle. How far is to far? What is the relation of the needle to the jets? I believe I have it now at 158 slow and 160 Main so we can forgo those questions. Thank you for your help!