Well, it usually depends on what generation your game...or show.. is but pokedex book says a Torkoal learns overheat at...well, it doesnt, you have to use a TM. The serebii website says the same thing so try to win a overheat TM in a gym battle or find one.
Overheat.
You can find the TM for Overheat in Stark Mountain. TM 50 can be found near two trainers called Stefan and Jasmin. You will need the HM move Strength to reach it.
Infernape does not learn the move overheat by leveling it up. It is only capable of learning it by using a TM.
I think it is overheat
Gym Leader Flannery gives it to you after beating her. Save it for a Pokemon youplan on breeding because you only get this AWESOME! move once otherwise.
I would really say "overheat".
it is either overheat or blastburn
you can find it in stark mountain.
Route 11
the best fire type move is blastburn 2nd is overheat 3rd is fireblitz 4th is fireblast 5th is flamethrower.
You get it after beating Flannery at the Lavaridge gym.