RE: BAX 95AX question
If any engine is very sensitive to needle settngs, and you're not running a pump or a tuned pipe, then you have a fuel-draw difficulty. The engine should not be particularly sensitive to the high-speed needle. However, operating at 7,000 feet above sea level can be helping you to have difficulties.
If an engine is properly broken in, and properly set, you should not be having to worry about tuning and "chasing" the needles. The engine should be pretty good for the rest of the day, unless you get a lot of temperature change. If your needle is hard to set, you may have too much propeller, too little propeller, too long a fuel system, a tank that's too low, and so on. Get it onto a test stand and work it out. The engine should be able to take a set and keep it fairly well. If you have to worry about dead-stick's every flight, then you have something 'way off, and it's likely not the engine's fault, but something in the installation or operation.