A couple of years ago, a new guy showed up with a MDS 46. He had the plane RTF. He was told to just fly the engine as is-- no break-in.

It sounded OK on the ground, but would dead stick after about 3 minutes. It did this for each of 3 flights. He was visibly disappointed with his first RC experience.

I went over to him to give my opinion about break-in( he was told that bench running / break-in was foolish) I suggested some more time running in and offered to help. I didn't see him again for about a year.

He shows up at the club field and ask me for help. He did run the engine at home after that first day-- he later told me. It did fine. A very consistent needle for the whole flight. We flew all day with no problems. I just think it needed a longer break-in than some other engine types. It had none of the leaking o-rings, bad carb or compression issues that we see so many of on the newsgroups.

I prefer the bench for all of my engines because you control its environment. Tank position is terrible in some airplanes-- especially for the newbies that are still learning. You can check to makes sure there is no foaming, air bubbles and have access to everything. I even suggest using a different fuel tank if you are trying to trouble shoot a problem. If it runs good on the bench, accept nothing less in the plane.

I have seen several MDS that ran just fine without all the extra time. That one just needed some TLC initially. I even have a soft spot for the MDS 68 after seeing a few-- very impressive engine of any make.

turbo