How do you catch moltres in leafgreen?

I used a Blastoise that knew Hydro Cannon and a Flareon, and 50 ultra balls (I ended up only using 4 of them) First, the most important thing to do....Get to Moltres and SAVE! After that, engage it into battle. Use Hydro Cannon on Moltres and hope Moltres uses Endure. If not, reset the game by pressing A+B+Start+Select until it uses Endure. It should only have one health left. If you have a Pokemon that can paralyze it then use it. After that, switch to a Pokemon that has the ability Flash Fire. (Moltres only know 2 attack moves and they are both fire, so it can't defeat it) I suggest Flareon. After doing all that, throw ultra balls until Moltres is caught.