Flare Blitz all the way.
Why? Because it gets an insane damage boost from Reckless, and since Emboar is so frail it is not likely to survive long anyways. Flame Charge probably won't help his Speed until it's been used twice, and it's weak as heck. Only use FLame Charge if you have another Fire STAB. Also, Shell
Bell + recoil move is actually quite effective; I use it on my BLaziken all the time. What you want is a few high power recoil attacks (which I assume are Flare Blitz and Head Smash) and at least one high power non-recoil attack, such as Hammer Arm or Stone Edge. My Blaziken currently knows Protect / Earthquake / High Jump Kick / Flare Blitz. Earthqauke is my high-damage move that will heal with Shell Bell, while Flare Blitz is my recoil (HJK is kind of in between the two).
If you're still uncomfortable with the whole HP loss thing, consider having a Wish passer. Two good ones are Vaporeon and Togekiss.
Ability: Water Absorb
EVs: 252 HP / 252 SDef / 4 Def
- Ice Beam
Vaporeon can switch into Water attacks aimed at Emboar, thus restoring HP. Wish can be passed to Emboar effortlessly, as long as your opponent doesn't predict his switch.
Togekiss@ Leftovers/Sitrus Berry
Ability: Serene Grace
EVs: 252 HP / 200 Spe / 56 SpA
- Air Slash
- Thunder Wave
Togekiss can switch into predicted Earthquakes, which Emboar can't handle. Togekiss is useful for Wish passing, but it has lower HP than Vaporeon. The upside is not having to go through a complicated breeding process to get Wish, unlike Vaporeon.