Tony

There are many more moving parts in a 4 stroke engine, including a cam, pushrods, and valves. More parts = more complexity and probably a greater chance of some part failing. Maximum RPM must be kept within certain limits or engine damage will result. However, they actually work really well. You have to adjust the valves once in a while, but that is the only extra maintenance you need. They are difficult to lube with after-run oil, so many owners neglect this task.

Running wise, a 4 stroke will often provide a quicker throttle response than a 2 stroke. Depending on the application, this may not be a big deal. For all-out high speed horsepower, it is hard to beat a screaming 2 stroke with a tuned pipe, but for 3D type maneuvers, a 4 stroke is often better.

I happen to love the sound of a 4 stroke and therefore use them in most of my models. I also love to tinker with them, so any extra maintenance is OK too. My advice: buy one and try it.

Sandy T