I had a 1.00NX as my first and last engine. It took a loooong time to break in. Many deadstick landings because of overheating...even while running on the rich side. The H9 superplug was a POS...way too cold for this engine. Switched to OS F plug and then it could hold an idle for more than 10 seconds. From that point on it was a lot of running the crap out of it to break in. Of coarse, as you mention, the limiters had to be removed. Then, after hours of run time and multiple jugs of fuel...I finaly got it to the point where it seemed broken in and reliable. Then the carb fell apart. ....I chunked the whole thing and got an O.S....no problems since.