The only way I can suggest is to paralyze it and get its HP down to red and then just keep throwing ultra balls (its possible with great balls but quicker with ultra balls) at it. Of course you could use your master ball but you should save that for mewtwo.
Moltres is not in ruby only firered, leafgreen and Pokemon xd gale of darkness can get moltres.
you cant. you have to have to catch them on Pokemon leafgreen or firered
In the Valcano on one of the 3 islands.
mewtow zapdos moltres articuno mew entei raikou suicune
You go to one island then go to mt emeber and he is deep in there
You can't unless you trade with somebody. Anyways Moltres is better
Go to Ember Island
Island One moltres is at the top of Mt ember.
On mt. Ember but you have to have strength and rock smash, and you must go to one island and surf
Moltres, zapados, and articuno are the three main legendaries in leaf green/fire red
The only way to get Moltres is changing it from LeafGreen or FireRed... I traded it, it is nicknamed Archen it is Lv. 89, it know, Fly, Flamethrower, Sky Attack, Heat Wave
Its impossible. The only way to get a moltres is to get it in pokemon leafgreen or firered and catch it on island 2 (I think). Then you beat both games (beat elite 4) and finish pokedex in pokemon firered/leafgreen. Once you did that, you have to trade moltres into emrald. You can only do this with gameboy SP's and regular gameboys, and you need a wireless connecter (or with wires, doesnt matter). thats the only possible way to get moltres in pokemon emrald. Hope it helps!!