Hi,

I have an art tech cessna skyline. I wish to replace the brushed speed 480 type motor. Could anyone please tell me, which inrunner from unitedhobbies to choose to replace the brushed direct drive? (I wish to use the original motor mount of art tech cessna.) Flying weight is app. 25 Oz.
Thank you for your answer in advance.

The problem with answering your question ( although you've provide on really important datum, the weight ) is that you have to decide what you are shooting for.

Engine/ESC/Prop/Battery choice is a balancing act.

How much weight would you permit the batteriest to add?

What kind of batteries are you going to use?

How do you expect to fly the plane?

How LONG do you expect the flight times to be at a minumum?

How much space is there in the plane for batteries and a second party ESC?

To help with your choices there are On-Line RC "Prop Size" calculators that permit you to play with the figures to come up with what you want.

Google for "RC prop size calculator" and "RC calculator" and you'll turn up a bunch.