Crazy ... the SF can fly with the OS40 for sure, but its easy flying around and nothing spectacular. If money is an issue then go for something cheap and very reliable, take the MVVS49, will run on 0% - 5% nitro and does not like or need high nitro content. You can run a 10x6 with a 46 sized engine but it might be over revving it. Here in Malaysia its hot and humid so we run 10x6 on our 46 engines. For the SF get an 11x6 you will enjoy the torque, better climb rate.

10% - 18% is pretty standard for use with a TT46/OS46/OS50 etc etc etc. Only the 'funny' engines MVVS/ROSSI/MOKI etc do not really like high nitro content. They were made to perform on low to nil nitro.

Breaking in a big issue, for the ABC ABN engines I will just run it slightly rich for about 1-2 tanks, not so rich till its blubbering. Then I fly it for a couple of tanks on a slighty rich, maybe about 750 RPM less than peak RPM. Please get someone to assist in running in if you are not sure.

Remember ... its not a toy.