My son and I both have the 1/4 scale Giles from G. P. We both use the OS 160 FX and really like it. Very reliable with plenty of power. In fact, I think this is at the higher end of the manufacturers recommendation. That said, I like more power than less. As the saying goes, you can always back off the throttle, but when you need more power with an undersized engine, well

By the way, the OS 160 also sounds much like a 4 stroke or gasser and is very reliable. Just remember to use the the larger sized fuel tubing in your gas tank and hose to the engine.

Good luck and hope this helps.