Does anyone know if the american 1290 can take led turn signals without having to fit an led flasher relay. I know the European bikes already come with led turn signals so I'm thinking that KTM wouldn't waste the money and use different flasher relays for the american bikes.

I just converted mine to the LED's that come stock on the Euro 1290. They work fine and is a easy install, plug and play. The resistor is built into each light so they blink at a normal speed.

the euro light are the way to go
plug n play
bright as all hell
my dealer ordered them for me