I've seen a lot of comments from people (and have experienced myself) that sometimes, the draw on these can get really hard. You may even have problems drawing hard enough to activate the battery switch. This is usually coupled with poor vapour.
One thing I have found, is that with these it really does make a difference which direction you fit the cartridges. If you look at the inner cartridge you will see it either has one or two straight edges, depending on the design, creating a gap. This is where the vapour is channeled. I have found that if you align these air gaps with the corresponding gaps on the atomiser (either side of the wire bridge), I get a much easier draw, and much better vapour. When it is aligned the other way, the draw is much harder.
Try it
The picture attempts to show what I mean (picture is of Evo parts, I assume the M401/2 carts are pretty much the same).
One thing I have found, is that with these it really does make a difference which direction you fit the cartridges. If you look at the inner cartridge you will see it either has one or two straight edges, depending on the design, creating a gap. This is where the vapour is channeled. I have found that if you align these air gaps with the corresponding gaps on the atomiser (either side of the wire bridge), I get a much easier draw, and much better vapour. When it is aligned the other way, the draw is much harder.
Try it
The picture attempts to show what I mean (picture is of Evo parts, I assume the M401/2 carts are pretty much the same).
