The 110 is a good strong engine, just like the other YS. I have a 63FZ, 110FX, 140DZ and 160DZ. My suggestion, feed it the proper fuel, prop it correctly, and spend some time getting it in tune. You'll be very happy with the engine. I think the #1 problem with those that have YS issues is wrong fuel, poor prop choice and settings out of wack.

As to your specific questions, it isn't exacly hard to tune, but it can take a little while, but it is worth the effort. Once set, it is pretty much forget as long as you don't change fuel and prop, as others mentioned. As for maintenance, a occasional valve clearance check and maybe a gasket and o-ring set once every 1-2 years, depending upon use.

Cheers.