Ok How should I do this? By using a vise or bolt the engine to a two bi four. Any Ideas I could use the help.

Most guys who insist on doing this will build a mock firewall with a throttle cable. They mount it to the bench with c-clamps or something similar, although some just screw the thing to the bench.

I can't be bothered with all that, so I just mount the engine to the plane, run a rich tank or two and fly it. Then you can begin leaning and HAVE FUN while you break-in your engine.

Seems like a waste of fuel to run-in on the bench.

I have to agree. I have never bench run an engine. I always put it on the plane and do as apexpert stated. I run a tank of fuel through it really rich and then fly it. I always keep all my engines running on the rich side anyway and I have never missed. I do this with all my engines, both 2 and 4 cycle. I am sure that there are those that will tell you that I am nut's, however it has worked for 30 plus years. Good Luck, Dave

I'll usually mount the engine to the plane also. When breaking in a new engine, follow the manufacturers instructions - not doing so could void the warranty on the engine.

Hogflyer

I'm old school so I always break them in on a test stand. NEVER squeeze the engine in a vice. The simplest test stand is just a bit of wood maybe 3/4" thick with a cutout that the engine can just neatly fit into. Then you can clamp the wood in a vice or whatever.

With a test stand you've got complete accessibility to all of the engine, there's no danger of the model suddenly moving, no servos and gear needed just a bit of wire connected to the throttle. The only advantage I can see of breaking them in while in the model is you can find all the screws you forgot to tighten fitting the bits and pieces

EXACTLY what downunder said. Don't squeeze it in a vise; it'll distort the aluminum and just tear it up in a short amount of time. Not to mention, engines have a way of vibrating loose between the jaws. Yep, had that happen too. Mount it on a piece of wood or the plane and be happy.

Dont forget load.
youll need to put a prop or some other type of load on the engine.
ya dont want it to just free spin.

Well,

That kinda goes without saying. If you do that, all you will have is pieces of your engine embedded in your flesh at various depths...or a broken engine with no compression and no warranty. I still don't know which is worse.....Mmmmm.

I would just like to add... make absolutely sure it is securely mounted and restrained. I have 6 stitches in my finger right now from an unrestrained bench test about 4 days ago now. I am going to vote for mount it in the plane from here on out.

"Unrestrained?" You started an engine without it attached to anything? I'm truly sorry for your injury. I guess you won't do that again.

I built a test jig from a piece of plywood, with hooks to attach the fuel tank with rubber bands, and a throttle pushrod and lever. It takes interchangeable "engine mounts," so with any new engine that doesn't fit the same holes, all I have to make is a new mount from another small piece of plywood.

I tightly C-clamp this to a full size picnic table before starting an engine. These things really pull! Make sure your plane is secure if you're going to run in the engine in the plane, too.

Phil

I always run mine in on a test stand too. I made mine from a saw horse, that I can fold up & take ot the field & run them there.

Tony.

Well, maybe it NEEDS to be said. I read a recent post where a newbie was thinking of running without a prop because he thought it would be safer. Argggh.

Nothing goes without saying. Remember, we're new at this.

Thanks,
Chuck

This is something that's just been brought home to me recently. I've been playing with engines for 50 odd years and it's pretty much second nature so sometimes what seems obvious and not worth mentioning gets skipped over. But a while ago I got an electric sailplane and reading in that area I know now I'm a complete newbie, idiot and dunce because I barely understand a word of what they're saying

It would never occur to me to say make sure you use a prop because it seems obvious but imagine my amazement when I read in an electric forum that some guys run in an electric motor. Not only that but they run them in with no load and in a glass of water! No, I'm not suggesting anyone tries that with an engine .

Downunder,
That burn in in a glass of water is for brushed motors only not brushless....