My 8 year old daughter races harescrambles. At the end of last season I bought her a 2020 raptor 90. I have had exhaust, port and polish, bore to about 100cc, bigger carb etc done to it. While practicing I noticed when she would take off full throttle it would take off, miss or spit, then go like normal. I took out the plug and it was slightly black but mostly a chalky white or grey at the end. Put in a new plug and went on. Fast forward to the race. She took the holeshot and was running good, but as she would come around to the finish line to get scanned for the next lap her quad would bog and stall every lap. When she slowed for the scan, as she hammered it to take off for the next lap, it would just die. I was guessing it was loading up on fuel and that was the problem. But as I thought about the old plug it made me think it’s either running lean or has a small air leak somewhere. I am not extremely mechanical but I do know enough to get by. If it is running lean could I just adjust the fuel screw?? Or up the idle screw a bit?? What is the best or easiest fix for that? Or what is a good way to test if it’s lean? Or has a leak? Any help of advice would be awesome. Thanks for the help.