One of the guys at the field was having this difficulty, where his new GMS .47 engine would put the fire out and stop abruptly when transitioning to full throttle. The solution was a fresh glowplug, a tank or two running time and most importantly in this case, new fuel. His fuel was suspect due to age.

Click on this [link=http://www.rcuniverse.com/forum/m_2290854/anchors_2290854/mpage_1/key_gms%252Ctransition/anchor/tm.htm#2290854]GMS Thread[/link] to see more information on tuning the GMS .47.