As the original poster stated, the LA engines (and their FP predecessors) are ideal engines for many applications. They're as reliable as anything, lightweight, fairly inexpensive, require virtually no maintenance and are about the easiest things in the world to adjust.

Where we get into trouble is expecting a bushing engine to perform reliably with fuels (specifically, oils) that are insufficient for the engine. Fuel often tends to be purchased on price alone, and little regard is given to the suitability for the engine in question. Bushing engines need oil, often times the more the merrier, and many of the "popular" brands of pretty colored fuels simply don't have either the quality, or quantity of oil present to make these things work correctly.

Strange that bushing engines were the standard in modeling for decades, and with the advent of modern manufacturing they are perhaps in their highest state of development ever, yet despite all this people flail and flounder with their operation. Huh?

Granted, there are some folks that would have difficulty operating a light switch, but I digress...

Run fuel that actually has a full serving of oil in it (20%+). Especially when the engine is new. If yours doesn't have a full oil compliment (probably not), then add oil to make it correct. Easy to do, and almost always gets your bushing LA/FP/Etc engine happily on it's way.