Join Date: Nov 2009
Location: Lander, Wyoming
One should never use the 'Ball End' of an allen wrench for loosening or tightening for Exactly this reason. You probably will Not be Able to drill the hard steel allen ball.
You may be able to drill an 1/8 inch or even smaller hole thru the bolt shank from the back side, then use a pin punch to drive the ball back out.
You may be able to use a cold chisel & hammer to catch the edge of the bolt head & jar it loose, then tap, tap, tap it around.
Or find a highly skilled welder to weld another bolt shank to the head of the existing bolt.
A buddy of mine purchased a used KLR in 2003. It had an allen ball broken off in the brake pedal bracket. Every so often we would use a magnet to attempt to pull & wiggle the allen ball out. We figured eventually road vibes & engine vibes would rub the burr down just enough that it would either fall out or the magnet would extract it.
The magnet finally pulled it out, this Spring!
Wishing you 'Good Luck'.
Modify at "YOUR OWN RISK"!
Still riding my 1987 KL650-A1. 84,000+ miles & counting