First off I would change the size of the tubing. If you are using 1/8" Id, then I would go to 5/32" Id. Most .60 to .61 glow engines run 11X7 props. A 13X6 seams a little large for a .65. Do you hold the nose up when you adjust the high speed needle? I do this every time I fly glow powered models. Lean it until it just starts to clear it's self out then stop. It might sound like it's not enough power when it is on level ground, but it will lean out when you get to altitude.....

Larry/Instructor