Be sure your concentrate is 'clean', run a foil test if necessary. Be very careful to properly preheat the center section before melting the load down. Never dry fire carts (which includes 'pre oxidizing').
FWIW, I'd concentrate on learning how to use the 2.4s one at a time. Not only can they produce some very impressive vapor if heat is managed well, but it takes some considerable skill to get two carts running identically (or nearly so) at the same time.
I was using it in the 5.0, it's pretty clean, but i'll do the foil thingy. How do i properly preheat the center section? fwiw, i am using a lighter as my torch won't take a fill.
once it's running, tips to get impressive vapor?