I have a Shuttle Plus with an OS 32SX engine.

Will it harm the engine to start it without the main blades, or should it only be started with the blades? I would like to see how it is running for the first time, without having the blades there.

the engine will not have sufficient load and you may overspeed the engine and damage it...

How do people break in the engines on the "bench?" do they not go full throttle with them or something? If they don't, how can they break them in?

Just curious!

Ernie

You can either bolt em to a plank and stick a prop on them or do what I do, run em in "in the hover"....

Typical "bench" break-in is on a run-in starnd, using a prop. I have also done break-in on my heli, with the heli clamped down, running with blades (and it is a good time/way to check your tracking too!). Others break-in flying, but obviously, that is not for a new pilot! The key is to heat/cool the engine to allow it to settle in - steady hover won't do that, but autorotations will! I have also seen pictures of folks who built "head loaders" so that they can run without blades, but I have never done this, so cannot make a call one way or the other. You DO still end up with spinning parts, just not full size blades . . . .

- Tim