The fast idle lever is there for this very reason. If your bike is new, it will probably get better after it is broken in a bit more.
I thought the fast idle lever was there for cold weather starts. Is 70- 80 degrees considered cold? Well, maybe in AZ where the temps are over 100 half of the year, but c'mon.
Hopefully it is just needs to be broken in more like you mentioned. It only has about 400 miles on it.