I bought a used Evolution .46NT never used in box someone tolled me I do not need to break it in is this true and are Evolution’s good engines going into my PT-40 MKII first kit.

I have heard that these engines are pre broken in but it couldn't hurt to bench run it and get your settings before the flight. It will also allow you to familiarize yourself with the engine.

I think the evolution is a chinese knock off of the .46FX, much like the magnum .46XLS, except with a different look.

I would run the engine just slightly richer than normal and fly it. The engine will tell you if it needs a break in if it begins to sag in flight.

I had an Evolution 40. Same idea.

"Broken in" is a misnomer. They come set so that they will start easily the first time. I still ran a number of tanks through mine on the ground and got things loosened up before taking flight.

After about the 4th or 5th tank an easier idle became apparent, and that's when it felt ready to go to the air. It idled reliably and transitioned well to full power. That's when you can say you've got it broken in.

You won't regret running it in some on the ground.

BobbyG

What is the harm in doing a bench test? I try to always run my car engines before installing them.

http://www.youtube.com/watch?v=0Vt7zogkTPg

Sort of confusing. You bought a used 46 you stated, never run in box, that then makes it not used? Anyhow I have 2 of them and they are excellent. They start easily lots of power and idle better than any I have. As has been said it will be worthwhile for you to bench run it if for no other reason then to get familiar with it. It may take a little to get it tuned properly but once it is it's great. You may find it desireable to remove the stops for finite adjustment of throttle.

The stops on the needle valves are more of a hindrance than a help.

After running the engine a while you will most likely find the need to remove the needle valve stops

With all the cooling fins on the engine it often requires a hot glow plug such as the OS A3 to run properly

There is no copying anywhere on the engine, so it isn't a clone of anything. There is a higher level of quality found in the crankshaft, con rod finishing, and chromed liner. The .46NT is balanced pretty good, but the .40 Alpha is better.

Edit to add: I've broken in 4 or 5 of the .46NTs. Right out of the box, they have a lot of power and run well. I would say that they run with a very slight ragged feeling to it, but really smooth out nicely on the next tank of fuel. I broke one in recently that seemed to run as smoothly as my older NT with lots of time on it. It was a nice surprise on this engine!