four strokes are not as hard to run as you think. they are just slightly different. valves need adjusting every so often but I usually wait till end of season. the 2 strokes are cheaper and more durable in a crash so for a beginner that is what I would use. this is only because the pushrod guides are a little more vulnerable to an impact. for awhile there I was president of the impact of the week club and was getting very good at disassembling and reassembling a 2 stroke engine. I beleive that trainers are meant to be abused and beat up in order to learn how to fly and that when you get proficient at flying them you can always change the engine if you arestill flying a trainer or you can use it on the low wing second aircraft. This is just my opinion though