I bought a DA-50 is my first gas engine, but the instructions does not say exactly how to break the engine.

can anyone tell me step by step how to do it

Yep,
Mix up 4 gallons of 32:1 with Lawn boy ashless, fire it up and get that puppy in the air ASAP. That's all there is to it. Running it on the ground will do more damage then good - motor needs air moving over it to cool it.
Oh yeah - and enjoy

What airplane is it in?

RickP

Thats my kind of break in! I bought one last winter for my Edge! Gotta get that thing done. Just can't find enough hours in the day! Have been flying by big PT-19 with the US 42 cc engine a lot. What a blast. Can't wait to try the DA-50! What an impressive piece of artwork!

There are a number of threads dealing with the DA50 that you will find interesting.
Check them out.
http://www.rcuniverse.com/forum/Does...1713333/tm.htm

http://www.rcuniverse.com/forum/DA_5...1958934/tm.htm

http://www.rcuniverse.com/forum/DA%2...1903161/tm.htm

Rick P I find it hard to believe that the prop can not provide sufficient cooling.... at a continual idle maybe it is not enough but balance of RPM range ????? I don't have the experience just observation of its airflow.

Those threads are good info but nothing to worry about. air cooled gas motors have always needed air to cool them. This means to get it in the air as soon as possible for proper breakin. No, the prop does not provide sufficient cooling!
As RickP states, use the Lawnboy for 4-5 gallons and fly! A good prop to start is 22x8 or 22x10 and move to a 24x8 after breakin.

I appreciate your answers guys is there something that i have to do to the engine. I mean do i have to move the needles right now is on the break in Stan. a friend mention something about a have to run the engine for one minute a full RPM and then open the hi speed needle for one minute to enrich the mixture to allow the engine to cool and then do it again

Sounds like you are trying to break in a glow motor. Put your gas in, Start the motor, allow 1 min or so for the motor to heat up then advance throttle to max. Check rpm, 6500-7000 is good. If you must, then lean out hi needle until rpm drops and then back needle off 1/4 turn. Go to idle, 1800 rpm is good. Again if you must, adjust low speed like hi needle. check for smooth transition. If the low is rich you will get burbling in the midrange. This is ok at first but you want to tweek the low needle a hair lean and check transition again. (Fly the plane after each small low adjustment). Point the nose into the wind and go! all other adjustments are to be done after flights. Small adjustments only. You want the motor slightly rich for a couple gallons. I'm sure you have heard a gas motor tick, tick, tick after shutdown from the heat. If you hear this on your airplane motor then your top end is too lean!

this the best advise that somebody game so far to break in the engine i will do exacly as you told me ...thank you