I just bought a DA50 and ran it in a motor stand for the first time. I am wondering if I should be running this engine in the stand or mount it in my new Wild Hare 540 (which arrives in November) and fly it to break the engine in. The engine starts and idles and runs good with only about 1/2 hour of time on it. It is running somewhat rich and with a 32/1 mix according to the directions. Also how much time is needed and how can you tell when the engine is broken in and also how do you tell when you have the carburetor adjusted properly. Is there any RPM that would be desirable to run the engine during break-in. Would there be any harm in running about a 22x8 or 24x8 wood Zinger on it?? I would appreciate any information.....Thank You....Bill

rcbill,
The DA50-R runs so well out of the box, that it should be run in on the plane, in the air. An engine gets much better cooling flying on a plane, than strapped to a bench, and the engine needs good cooling when running in. Yes, it should run a little rich during the run in, but too rich is not necessary. The low needle should just be so rich that you get a slight stumbling when throttling up, and high needle should just be set so that the engine doesn't surge at WOT. It is a bit of a pain to run these engines in, because you should stay away from 3D or full throttle as much as possible but you want to run as much fuel through it as fast as possible. Flying some IMAC sequences is a good way to get fuel through it fast. Don't make your full power uplines to long, have a fairly high idle in the air, run a 22x8 or 22x10 prop, not a paint stirrer like a Zinger. Run about 10 gallons of run in fuel (Lawnboy 33:1 mix) through it, you can lean the needles as you burn the fuel, you will feel and hear how the engine becomes more responsive and stronger, as you burn more fuel. The black mess out of the exhaust will also become less as the engine runs in. Fine tuning of the engine is best learned from a fellow modeler at your field, or perhaps you will pick up an ear and feel for it as you get to know the engine better.
DKjens

I recently built a test stand for a brand new DA50 for the sole purpose of making sure I knew how to start it easily, and that it ran right before putting it in a plane. Three times I started it and only ran it for less than 60 seconds at lower RPMs with a break in prop (NX 21x8 I had laying around, I won't fly with this prop). The previous poster covered it very well, don't break in this engine or any gasser on an engine stand. They can burn up and besides that it takes so long that it's impractical.

BTW, mine started just the way the instructions said and ran like a dream. Sweet ***** engine.

Thanks for the help so far. I do have a couple more questions. Should the engine four stroke from being rich while being broke in?? I know the fuel/air mix is rich - but is that too rich?? Also I know the tank should be pumped out at the end of the day but should the engine carburator be run dry also. Should the carburator be kept dry during winter storage?? Once again any info would be appreciated.

THe DA 50 won't "four stroke" as the ignition fires it each stroke. If you run it too rich it will complain at you. Just run it a tad rich with a tad more oil.