I agree with Mike, YS engines can take a bit of experience to get running right and to keep running right. Plus, they are EXPENSIVE!!!

I'm not going to comment on the merits of the way engines run, and the differences between 2 and 4 stroke. But I do want to give you a bit of food for thought. I know that you're still in school and money is a bit tight at times. Most 2-stroke engines can take a lot of abuse when they crash. Heck, I've completely buried a 2-stroke in the dirt and all I did was clean the dirt out of it and was up and running again. Many times a 4-stroke will take SEVERE damage in a crash. Remember that a 4-stroke engine as a lot of delicate parts (valves and valve trains) on the top and out front of the engine, the very places that hit the ground first in a crash. Most times when a 4-stroke crashed the pushrods will need to be replaced, at the very least. We had one at our field last weekend that actually sheared the valves and rocker ams clean off the head, the only thing that engine was good for anymore was a fishing anchor!!!!!

Just something to think about.

Ken