I am new to the hobby and need to find out the best way to break-in a new engine. An OS 40 LA. Appreciate the advice!!!

Run a tank through the engine at full throttle and then she'll be ready to fly.

Run the first tank on the ground so you can get to the controls easily. Then for the first few flights keep it on the rich side. Lean it out gradually as you get more runs on it.

Running in an engine properly is a bit more involved than one tank flat out then go fly

Follow the instructions that came with the engine first but even they rely on a little experience. The most critical thing is having the mixture set just right and for running in this means at a point where it's at a rich 2 stroke. But if you've got no experience this won't mean a thing to you so I'd suggest you go to a local club and ask someone to show you what it is. Ask to speak to one of the instructors who'll either show you or point you to someone who's got some expertise. Or just watch for a while and if you see someone hand start his engine then he'll be the one to approach

Well that would be the best way to go about things of course...

I Have a OS 61fs that is 10 yrs old and i first put it on the plane and fly it , I think it has lasted so long becuse i allways run it just alittle rich it leaves a little more mess but windex is cheaper than a new moter , there is a man in my club that runs a tank of fuel a new motor then it's balls to the wall and he goes thru alot of motors and i'm still flying with my 10 yo OS and i have many more OS motors that fly fine out of the box , so my advice is allways run just a little rich till you learn more about motors and do like i do and let someone else burn up there motors and learn from there mistakes