Safety wiring countersunk cap head bolts

I've got a ton of things to drill and safety wire on my latest project, and damn near every item is a cap head bolt that is countersunk into the bike. Countersunk below the surface, and almost no room between the bore and bolt head OD. What's the trick with these? On a couple I could cheat, thick washers and longer bolts, wire as normal, some areas I don't necessarily have the clearance to have bolt heads sticking proud of the casting.

 

Are dabs of silicone/ RTV still a thing?

 

I've done the following a few times so an angled hole didn't have to be drilled.

I've bought flange head bolts that are predrilled for safety. The flange will be too big to fit in the counterbore hole so I'd turn down the flange until it fit. I have to use a thin wall socket to stay on the head while going in to the counter bore.

This will work for bolts that can stand proud of the counterbore as the head will be slightly proud.

As for the ones that have to be flush. A sharp drill bit (center point probably) and patient....

 

I don't think Moto America will let me get away with a dab of RTV, oil/fluid drains are specifically called out to be lock wired only. Brake caliper bolts can be wired or use 'a secondary retention mechanism' but I suspect that's to allow clips which are otherwise forbidden.

I may need to find someone to weld me some tabs so I can wire the drain on the swingarm to something.

 

Just get different hardware for the drain bolt.

 

The issue isn’t drilling the drain bolt, that should be ‘easy’, the issue is there’s nothing nearby to drill to wire it to. No other fasteners, protrusions, etc. There’s also no place for spools, so some amount of re-engineering on that swingarm is going to happen.

 

Put 1/16” chamfer at the top of the counterbore. That should leave space for some .020” safety wire near the top ot the socket head cap screw

 

To be clear, you mean the fasteners are V shaped (countersunk screw) or are they socket head cap screw? (counterbored ⌴).

If counterbored/socket head cap screw, drill through the top face, then through the side through to the internal hex.
If countersunk screw, it's the same but more difficult since the face of the countersink is 82-90 degrees.
This would benefit from a drill fixture or jig.

 

Oh, yeah, terminology fail on my part, counterbored socket head cap screws. The rear brake in particular will be a pain to drill that way as the bolts are pretty far away from the edge, and it's got a bit of a curve to the casting.

 

If you can share some pics, I can have a look and provide some options.