alright, just on what i have learned coffee flavor i would assume to be dark juice. bad. high vg content. LOL... bad... so yes, i would say juice may very well be the culprit in your failed carto experience... i was lucky. the first time i tried it, i had a juice that worked... then a LOT that didnt... then another that worked... ya know? lol
stickers... heres why you will wish they stayed on... when your cartos are running efficient and vaping well and are yummy, they will start getting hot, like not kinda hot, but "DANG did i blister?" hot... that bare metal will give ya a zinger on an efficient 8 second battery blinking vape... obviously if u slip in a 902 mouthpiece, this soesnt matter... but if you want a traditional cig sized contraption, you can bite in your teeth, the thick sticker also reduces teeth on steel. stickers are indeed dentist reccomended. lol
also something to note... i remove (and i believe Gar and others also remove) the clear rubber donut inside the carto that sits atop the wick material.
now as far as something that has worked faaaaaabulously for me... my single "go to" juice when my cartos have to work quickly and efficiently, it is this (word for word from my order):
Nu-Juice Liquid Refill
Flavor
Banana Coconut
Flavor Boost
Double Shot (Strong)
Blend
Renu Custom Blend (55% PG / 35% VG / 10% Flavor Enhancer)
Nic Density
11mg Medium
Throat Hit (Lowers Vapor Production Adds Throat Hit)
Smooth
now i dont know if tony is upset by people posting info about non MV products that work well with his, Tony if u do, sorry, didnt know. i can remove if u desire.
anyway, this is the place i order it:
USA Made Vapor Renu
everything u buy from them is big plastic 30 ml bottles, so you might have LOTS of juice sitting around... i have about 150 mls sitting here right now that are NOT carto worthy juices from that same company, so its a crapshoot.
the GOOD news is that the 30 ml bottle as i configure them usually run about $8, so you can afford to have some duds...
besides, i like to use all my extra stuff for trying mixes and playing with dripping.... or for trading! i'll have to put up a trade list soon, eh?!