I used to have Kuryakyn LED blinkers, and they would do the same thing when I keyed on. Never figured out why, but they always worked fine, so I never worried. I will tell you this, I burned out my control module by using my four way flashers once. Kuryakyn rep told me that they don't advise using your emergency flashers for more than a couple minutes as that the module will quickly overheat and fry. Just an fyi.......

 

I have a 2005 Road King, no security system and stock blinkers. I have noticed that my bike does the same thing, not sure if it does it every time, but I have seen the blinkers flash 2 or 3 times and then stop when I turn on the ignition. I also have the Daytona Twin Tec ECM, I think I will give their tech support a call and see what that means.

I just checked and it does not do it all the time, just sometimes.