Broken Bolt in the Engine

Good motorcycle protection (cages, sliders, rails, crash bars) comes with quality high-strength fasteners. Such fasteners don't bend but break under critical load, which is very important when the motorcycle crashes or slides. If a bolt bends, it damages the mounting point and the thread. Often after removing low-quality cages you can see that the mounting hole in the engine has become oval: this happened because the mounting bolt bent and deformed the soft aluminum alloy the crankcase and frame are made of.

Sliders on street motorcycles should also come with high-strength fasteners. If a slider hits an obstacle or falls into a hole while sliding, it should break off; otherwise the mounting bolt will bend and pull the frame lug with it until it tears off or deforms. If a mounting bolt broke off in a crash, removing the broken piece from the engine won't be easy. It's good if the piece sticks out of the hole. In that case you can weld a nut or a handle to it and unscrew it easily. If the piece is recessed, you will have to drill a hole in it, into which you can drive a special extractor.

• It is best to drill a hole in a high-strength bolt with quality bits, carbide or cobalt.
• Drill at low speed, constantly cooling the bit in water. It's important not to overheat the bit, so be patient.
• If the bit doesn't cut at all, try a small-diameter bit first and then widen the hole with larger bits.
• When the hole goes the full depth of the piece or 2–3 cm, you can drive in the extractor. It's a good idea to spray WD-40 on the thread first so that the piece unscrews as easily as possible.
• Usually the extractor unscrews the piece easily, but if it doesn't, you can heat the piece with a heat gun, which should make it turn more easily in the thread.

We spent quite a long time drilling the bolt with a cobalt bit, but in the end everything worked out.