Mike-

I'm sure you find this all very confusing. Setting up these things can be a real trick, especially when you have a used engine, because you never can tell if the arm has been moved, or even put on upside down so it works backwards. That's why I recommend blowing in a fuel tube connected to the the carb nipple while cycling the throttle lever. At the low end you can hardly blow through it and at the high end you can feel a definite flow.

So to reiterate, you idealy would have your radio programmed so that low throttle is at 10% and high end is at 90% with a straight line drawn between those points.

For the mixture arm, the low end should be at the point you measured before. The high end should be 10mm closer to the firewall assuming the mixture arm is pointed toward the bottom of the engine.

When you go to the field, get the top end right first and adjust your straight line accordingly. You should be pretty close then, maybe good enough to fly.

-Ron