Hi, My friend just bought a new 2001 YZ426. In 1/8 to 1/4 throttle when he's not trying to accelerate but just cruise (on his way to the MX track) the engine doesn't work smoothly. His jetting is: main - 162, pilot - 42, needle - 3 rd. position from top. He has tried playing with smaller pilot jets, different needle settings and setting the idle mixture screw but it has not solved the problem. Has anyone else encountered this problem and has anyone found a way to fix this ? Thanks, Efi.