I just got thru breaking in a Thunder Tiger .61 PRO and is a very reliable, low idle engine and it turned an APC at 12,000...this engine was very easy to start and was good on fuel. I also broke in a Super Tigre G.61 and it turned the same prop at the same rpm and was very easy to start until the sinch bolt the holds the carb in broke, and the muffler bolts kept backing loose. Even with all the bolts tight and it running good it leaked fuel from somewhere...probably the front bearing. Even with all the problems I had with the ST I would still buy another because there are what I call small problems. The TT.61 PRO ran perfectly from the very first start all the way to the bottom of the gallon with no leaks and no bolts comming loose.