Front brake grabbing/pulsing cure?

It's quite possible the rotors are warped, especially if you have used heavily sintered aftermarket pads.

That said, do your best to confirm the problem. I assume you've inspected the discs and they look clean?

Try cleaning the discs with brake cleaner and some fine wire wool. Dress off the pads with some fine grade glass paper.

With the front off the ground spin the wheel. You may be able to hear the discs running to the pads, you might even be able to see it if it's bad.

As with any brake problem, a quick bleed of the fluid does no harm

Warped rotors don’t happen very often on the sd, but I guess it’s possible.

Put the bike on a stand so you can rotate the front wheel.
Hold a pencil against the forks with the point of the pencil gently touching the outer circumference of the disk.
Rotate the wheel and see if it touches /increase gap.

Put the bike on stands and spin the wheel. If it's warped than you should be able to tell by spinning the wheel. If you don't notice anything out of the norm I would bleed the brakes.

Brian

I cleaned mine and the pulsating went away. Now the brakes are dirty again and the pulsating has returned.

after I modded the button/springs the wheel spun freely by hand.

I have 20k miles on the replacement rotors and no pulsing. the braketech rotors are noisy at low speeds though. the rotors are free to float except in the direction of braking forces.

I pulled my brake system apart today.
The calipers are good, but I'm going to replace the piston and seals anyway while I'm at it.
The master cylinder on the other hand, not so good.
The inside of the master cylinder has scratches/scrapes inside it.
Pushing the piston into the cylinder causes a jerking action that is ok once its in a bit.
This make complete sense now as the piston is jamming at the end of its stroke just when it should be releasing the last of the pressure, causing the pulsing in the brakes as the disc's rotate and push the pads back and the piston jams and pushes again.
Only a guess at the moment, so I will be ordering a new "hand brake" from KTM.
Stoopid KTM only sell the complete unit, you can get all other components, from bleed nipples to levers, but you can't buy the master cylinder separately.
So after this is done hopefully my brakes will be back to normal.
New discs, new "hand brake" and new piston and seals.
I had always dreamed on owning a bike with Brembo's now I'm cursing them.
35,000+k's and they're f**ked.
My Yamaha YZF600 had 100,000+k's on it and the brakes were as good as the day I got the bike when I sold it. Only replaced the lines with steel ones and got new discs when they wore out. No issue with the system itself.
My respect for Brembo's has gone.