I used to fly and build 35 years or more ago.
I got back into this by purchasing a couple of used trainers from a guy that wanted out.
I want to upgrade someday to a Spektrum DX6i. It comes with a standard receiver and no servos. So I looked the selection of servos and I guess they go by torque ratings for selection.
So I took a look at some kits online and I don't really see in the instructions where they tell you what servos you need?
There are so many types of kits with the microlites and park flyers out there today and for me it's confusing.
Am I missing something?

If the planes are "40 size" or "60 size" trainers (typically 5 to 6 foot wing span) they will use standard servos. Standard servos usually have 40 to 50 ounces of torque and may or may not have a ball bearing on the output shaft.
Examples in order by brand:
Airtronics 94102Z or 94322Z
Futaba S3003 or S3004
Hitec HS-311, HS-322 or HS-325
JR Sport ST47 or ST47BB
There are lots of other choices but these are good basic servos that cost between $10 and $20 each.

If the planes are smaller than 40 size, or bigger than 60 size, post some details about them and someone will know what they need.

You misunderstood my post. My trainers have servos and all.
I am talking about the future and kit building in general.
How do you tell what size servos to use a in kit?
The instruction manuals I am looking at online don't seem to tell you.

KrashKart,
One of your best resources to find what to use is right here, RCU. Like you post says, there are so many different plane that it's hard to say what to use. And even for the same plane what type of flying you are going to do will determine what servos you should use. But a good rule of thumb is that most 40-60 sizes planes are fine with standard servos (Futaba 3003, Airtronics 94102, etc....).

Ken

I've only built three kits, and am currently working on a fourth. All but one had servo recommendations in the manual (they all just said "standard" servos). The one that did not have recommendations had clear enough pictures to be able to tell what they used.

I think selection is more complicated for small models than for 40 and 60 size.

If there are no recommendations in the documentation, post a question with as many specifics as you have and you'll get lots of suggestions.

Yes, i figured the bigger planes used the standard servos.
Maybe I am just looking at the wrong models and any model that does not used a standard receiver and servo setup and requires something lighter is going to tell me in the manual for that specific plane. In other words if it requires something other than standard it will say so.
I could be trying to make this harder than it is.

My Tower Hobbies Uproar 60 is the kit that didn't have recommendations. The plane has huge control surfaces compared to everything else I've had so I expected to need "high torque" servos. All of the pictures in the book showed Futaba S3004s. I have a drawer full of Hitec HS-425s which have specs similar to the Futaba so I used them with no issues at all.

There's no doubt that some manuals are better than others. If there's any doubt at all, just toss the question to RCU. If there's a link to the plane available, that always helps. For just about anything ever made "someone" who reads these forums has built it or flown it.

Go to towerhobbies.com look at the different servos and their torque rating. Get their 2010 catalog for a complete list.

Somewhere in the list of needs the servo torque rating is given. The servos listed above are great for 60 size and less, is you go any higher, the tail surfaces may need a higher torque amount. On my 160 size, I use 133 in oz on the rudder and elevator, 72 in oz on each aileron, and a standerd servo for the throttle.

Using a 2.4 GHz radio, response time is reduced. If you use digital servos with your digital system, You will notice a much soother and accurate control that futher reduces your response time from the transmitter to the airplane.

Realize if you want a spekturm system get the JR servos. (Just get the JR radio, higher quality parts and more options for the money! There are several spektrums on a recall list)
JR owns spekrum but the quality differs!!! My friend found this out.

I use a Futaba 7C.