I have a .60 4* ARF, and I am planning on putting in an O.S. .60 LA, will that be a decent engine for it?

Did you mean the .65LA? The .61FX would be my personal choice. I have 2 of them on different planes and they are regular powerhouses. All assuming your stuck in O.S.'s world, like myself. Rest assured others will chime in with 4 stroke recommendations or other brand names as well. All in all, the .65LA would pull this size plane very nicely.

depends how you want to fly it.lol
what prop you use ?
how lite you build the plane?
being only a bushing engine ..it's not going to pull it to the moon.
but it has plenty of power. use 15% or greater if you want more power
beside...you don't need to be on full throttle all the time
when flying... Make the loops nice and round.lol

i used a magnum .61lx with 15% ..has plenty of power.
but the thorttle sticks (burrs in the cabb..out of the box)
i also had to jb weld the carb to the engine.
and it dosen't matter how the LSN is adjusted...

IMO...o.s are more reliable and other manufacturer over rate thier
engine's power.

yes, i meant the .65 LA.

I want to fly it and get it do all it can, plus more, mainly (if I can) Hover
What size prop should I use?
Im building it as it says to, so an average weight.
I plan on using 15% on it

First, the 4* is not DESIGNED to hover. I am not saying it won't, just that it is not designed to.

Next, IMHO, the 65 LA is not going to have the power to pull the plane out of a hover. You should be able to hover at 3/4 throttle or less so you have the reserve power to pull out of it.

As for a prop you will need to experiment. A good starting point (provided the LA will handle it) would be something in the 12x4 - 13x4 range.

If you want to TRY to hover this plane and/or perform "authoritative" aerobatics, you really should have a ball bearing 61 - 75 2 stroke or an 80 - 91 4 stroke.

Hope this helps.

I would suggest the .74 Fox or Tower. But the .65 LA would be close, much better engine than the FX power wise.

I flew mine with a YS91Ac originally and switched to a TT .61 2 stroke. I think it's a bit under powered now but with the YS I couldn't get it to stop on the runway at idle.

I think the TT 91 fs or a 75 size 2 stroke would be best for what you describe.

Engine choice is all about dollars, power, and weight. Considering only the OS line it breaks out like this:

The 65 LA puts out 1.7 hp and weighs 18 oz. The .61 FX puts out 1.9 hp and weighs 19.3 oz. By way of contrast, the .50 sx puts out 1.8 hp and weighs 13.8 oz. (the weights are from the OS page and may or may not include the weight of mufflers. The weight of the muffler only becomes important if other engines are being considered since all the OS ones should be consistent with or without)

The cost varies depending on where you buy the engine. With these three, generally, the .50 is the most expensive (it's a ringed engine).

Now you need to keep in mind that at some point in time, you will probably want this engine to go into another ship. In all probability, you will desire more power/weight as time goes on.

If just the three engines were to be chosen from, I would pick the .50 . Now, in fact, I would consider other engines on the same basis, with a lot of attention to what the engine might go in, in the future. The .65 would probably be my last choice among most engines since it's power to weight ratio is poor compared to most. When you compare 2 strokes to 4 strokes, everything changes again.

If you think 40 size profiles are in the future, the .50 is a good choice. If, on the other hand you like larger planes, you might want to consider a .91 4 stroke.