What are you trying to run this in. A 2S lipo pack isn't much voltage and with the 2.5d and a good battery pack, you're only looking at about 14,000 rpm. It's gonna be a dog, unless it's some type of crawler, in which case it'll probably be too fast.
Is this going in a 1/10 or 1/8 scale? If you're talking a Monster truck, like an emaxx or revo and two 2S2P battery packs, then the 1512/2.5d should be a nice motor to run with the quark.
Oh, sorry. I pulled the post off of the "new posts" search. I guess I should have caught that.
The batteries that you linked to aren't that best that you can get for the price. The Orion 4800 packs are only 15C packs and aren't made up of the same 20C cells that Kokam uses in their 2S 4800 pack. For better bang for the buck, check out the trakpower packs.
From the information that I've gathered, the 1512 should be enough motor for the Revo, although a better choice would be a 1515/1Y for speed and power, if you're gonna stick to 4S lipo; or the 1515/2.5d for more conservative speed and the ability to go 5S lipo in the future.
The kv rating of the 1Y is similar to the Feigao 7XL, which I've run in both trucks and buggies. It makes for a very fast setup, but you have to make sure that you've provided for keeping the esc cool and that your battery packs can keep up with the current draw.
The only dumb question is the one you don't ask. Anyhow, you're not alone in not fully understanding this stuff. That is why I'm in this thread...to learn more. So ask away :018: