I am replacing the ignition barrel. Somebody tried to steal the bike some years ago and I've finally got round to replacing all keys and locks. But how on earth does one remove these bolts? My 4mm socket doesn't fit it and 5mm is too large.
They are security or shear bolts, designed so that they cannot be removed. As they reach the correct tightening torque the hex head shears off. The only way to remove is drill a hole in the centre and use a stud extractor. You may be lucky and be able to cut a slot in the remaining head and use a screwdriver. Best of luck!
Thank you all for the advice. I ended up getting a set of stud extractors of various sizes and an HSS drill bit set. I managed to break two 2mm drill bits and snapped off the tip of the smallest extractor bit but got both bolts out in the end. In the process i learned that when using the stud extractor it's necessary to drill a deep enough hole into the bolt or you end up overstressing the bit.
Hi Adam, the bolts are indeed shear bolts, when fitting them once they reach the correct torque the bolt head shears off to slow down any attempted theft, what you need to do is first use a centre punch to mark the centre of the bolt, then use an anti clockwise drill bit to go to a depth of approximately 8mm, then use an anti clockwise extractor, the shear bolts are thankfully not torqued high and come out fairly easily. You can get the correct drill bits and extractor from bikers toolbox, you will of course need a drill with a reverse motor capability, a lot of people use a conventional right hand drill bit and then wonder why they have difficulty removing studs etc. Ride safe all from an ageing Rocker.
