clamping of throttle cable

I notice in your first link that you are using an AN3 bolt to clamp the throttle cable, instead of a M5 cap head bolt (as supplied by Rotax).  Did you have to drill a hole yourself under the head of the bolt?  I have seen a variant of AN3 bolts which have a hole under the head, but I cannot find the code.  Did you use such a bolt?