As I recall, Torkoal can't get Earthquake, but Numel/Camerupt can.
Anyways, this is my suggestion - what I do when I use Torkoal.
Torkoal @ Quick Claw
Curse
FireSpin
Flamethrower
Iron Tail
You'll notice that you're strong against Rock types, but still weak against Water types - but if that's a problem, try swapping moves about like this:-
IronTail->Sludge Bomb
Curse->Amnesia
This will mean you have a 30% chance of poison with SludgeBomb, then you trap them with FireSpin. The only types that can't be poisoned are Steel and Poison - Steel is weak to fire, and most poison-types don't have huge stats anyway, with the possible exception of Weezing. However, Weezing only has an average level of SpDef, so that's not a big problem.
Finally, if you really can't conceive using FireSpin, just swap it for Protect - works well against pokemon who use Dig/Fly/Solarbeam/SkullBash, etc.
Either set seems to work well. The Quick Claw has that chance of getting past it's low speed, (and the Curse problem), and that's why I favour it over the other Hold Items.