That .25 LA is a great choice. It's plenty powerful for its size, easy to tune, and reliable.

Engines with bushings instead of ball-bearings run best with plenty of castor oil in the fuel for lubrication. If you buy fuel with 100% synthetic oil, it won't really hurt anything, but the engine won't run at peak efficiency and it may tend to leak a little bit of fuel.

10% nitro fuel with 20% all castor oil lubrication is ideal for flying bushing two-strokes like the O.S. Max LA series, the Thunder Tiger GP series, the K&B Sportster series, or Norvel bushing engines.

The problem is that many local hobby stores don't stock fuel with 100% castor oil lubrication or even 50/50 synthetic and castor blend anymore. Most of the off-the-shelf fuel tends to be either 100% synthetic lubrication or 80% synthetic and 20% castor oil. Castor oil is thicker than synthetic lubricants. Castor oil is great for protecting your engine for this reason, but it can be sloppier to clean up off of the side of your airplane. Many pilots avoid castor oil simply to make cleaning their plane at the end of the day less of a chore.

If you can't find fuel with better than 80/20 synth to castor oil content, you can simply buy extra castor oil from the hobby store or from your local pharmacy. Add a half a cup of castor oil to your gallon jug of glow fuel, and your bushing engine will run smoother, build better compression, leak less fuel, and run stronger.