RE: .12tz carb restrictor/ break in on crt.5
First, we'd be very skeptical of your "break-in" method. We NEVER idle an engine more than a few seconds before we start to drive it. Idle it for a tank or more and you'll have a short engine life. You must DRIVE the engine! We run the engine up and down the parking lot, going up to high throttle and back down, gradually leaning the high-speed needle as we go. It all depends upon how the engine sounds and performs. That's the key. Temp is irrelevant until you have the engine properly-tuned. Then temp can tell you if something's going wrong, but it's not a key to tuning. Use temps to tune your engine, get short engine life.
Adjust the needles as necessary. You can't get a good low-end tune until the high-speed needle's properly-adjusted, but you can start to adjust it to help with idle and midrange.
If the engine's quitting at 1/2 throttle, then it's likely much too rich on the high-speed needle and the low-speed needle. The "factory" settings are only very gross starting points, and nowhere near the final adjustment point. That, you have to find while running the engine.