gcb

A few comments:

mred33, I know what you mean. Before combat became so specialized it was an "add a streamer and fly whatcha brung" type event.


Tom, I remember a newby with a Buster one time saying that Buster was an appropriate name for his plane because he took 'er up and proceeded to buster.


yokozuna316, almost any new engine can run on half and half. Well used iron/steel engines that have been run on all-castor often maintain some of their compression with a varnish seal that builds up on the porous iron piston. If you run with some synthetic, it will remove this seal and you may lose some compression. If so, you can get it back by switching to all-castor.
If the engine has been run on fuel with some synthetic, it does not have the varnish buildup and can be run on on castor/synthetic mixed lube. I did not mean to scare you about synthetics. I would caution you to not use all-synthetic, especially on an iron/steel setup because of the running characteristics of iron/steel. I personally would not run all-synthetic in ANY engine just because of the "insurance" that castor provides. Most of the time I use all-castor...even in ABC engines.
I think SIG's high castor oil content fuel is 25%. That should be adequate for any engine, although some prefer ~28% for a Fox .35 (a special condition). The Fox .15 BB should run well on 20%-25% either all-castor or 50/50. I would recommend 15% nitro for sport, more for performance.
Additional point: some manufacturers (not SIG) quote oil percentage by weight instead of volume, so their 18% by weight may only be 14% by volume.
And remember, this is only one opinion, check with the flyers around you.

George