tIANci, I suspect that your hot-humid tropical air is robbing your TT 46 of power. I have seen over 13,500 with an 11-6. A 10-6 should hit ~15,000+ in flight, which is great fun -- for a while. It beats hell out of the rear crank bearing if you keep it up. A 10-7 is somewhat easier on the engine & even faster