It's an easy fix but that's not a big issue as in the case of the Dyno your 5th line isn't loaded so it doesn't affect the flying characteristics of the kite. In other words it's only for the safety system and can also be used to help relaunching the kite. You should have some pigtails adjustments for your fifth line about a 1/3 of the way up from the bar to shorten it, this will get rid of the slack which can get annoying. Also a good opportunity to tune your lines as often your lines will get uneven in length (back lines vs front lines), which could explain why you have slack in your 5th line as well.

Ah I see! It was my understanding that they switched to a loaded 5th line from the 2012 onward, although I could not find an abundant amount of information of this online. I have adjusted the pigtail on the 5th line, although it is still left with a considerable amount of slack. The bridle line is approximately to spec as well(actually shorter than listed on the line). I did happen to notice that it has a tendency to oversheet in light wind, but some of this may just be me getting used to the new setup. Thanks for the reply so far.

Only the 5 line specific kites require a loaded (tensioned) 5th line, Vegas and Rebel. On the 4 line kites Evo, Fuse and Dyno from 2011, the 5 line compatability is achieve by having 2 knots on the front bridle. Lower was for 5 line, upper for quad set up.
5th line helps with lightwind relaunch, self landing and allows the kite to flag to a single line. Normally if you tension the safety there is only about 2.5 cm slack. Don't worry to much, go kiting

ralfy said..
I received a 2012 dyno 13 m second hand. It was supposed to be with 5 line bar but came with a four line north bar, while the connecting line frm the middle of the leading edge was dangling free. As i intend to use it for light wind i added a fifth line for better light wind relaunch. i made it non loaded with a bungee part so it does not hang sllack. Something does not feel right about the kite. it is quite hard to turn after an aerial transition. Seems slower than 11 m ozone edge, and most of all seems to back stalll after landing such that it barely manages to rise again. It behaves over-sheeted but i dont think it is as it pulls upwind nicely. I am wondering whether it is to do with the steering lines pigtail settings, or maybe the fifth line should be loaded?

There might be a little bit of tension on your fifth line when you bar is sheeted in, which would explain that behavior of the kite you describe. Try disconnecting the fifth and fly it and see what happens.

Otherwise it could be down to simple line tuning issues (back lines too short, front lines too long). If not then it could be down to the bridles length or adjustments...and lastly could be the kite itself...

I just realised there is the usual steering line position adjustment also with this kite. I understand why you would get more depower and more bar pressure with the steering lines closer to the front lines (further away from the trailing edge), i have never figured out why and how it would affect the turning speed of the kite. I guess i need more turning speed so that the kite when coming down after transition turns back up rather than almost hitting the water and loosing power.
The ratio between front and steering lines cant be the issue as i can vary that on the depower cleat.
the fifth line is under no tension and cant be it, unless it should have a bit of tension. On the Rebel one can make little effective elongation of the fifth line by say 4 cm and improve the light wind power of the kite. in stronger winds the extra 4 cm makes the kite scoop too much air