Hi there.
THis is my first time trying to contribute so be kind. (Only noobs flame).
In Hellfire Peninsula at the new place for dailies, Throne of Kil'jaeden, the Fire Elementals seem too have a very high drop rate for mote of fire. Also they spawn pretty fast. There will be alot of ppl doing the new daily there but alot of them just leech your kills coz they get their quest done even if they dotn get the loot.
Hopefully this will be useful to some ppl. Cant use the search function since im a leecher. GL with the Primal Fire farming .
//Noobinator33