The front rotor on my 2009 SM610 was cooked so I took it to a shop to have it machined today. The guy didn't have access to a heat source and destroyed the heads of the four rotor mounting bolts trying to get them out. We ended up having to drill them to get it off and machine it. Luckily, the threads in the hub didn't get damaged in the process and we were able to mount the disc back up with four matching M8 bolts he had at the workshop. When I got back on the bike the speedo / odometer were reading almost exactly double what they should have (~120km/h at 60km/h, ~200km/h at 100km/h etc.). When I got home I inspected it thoroughly and couldn't see anything wrong. The manual specifies ~2-4mm for the gap between the magnet and sensor and this was correct. The only thing that's changed is the rotor mounting bolts. I used a spanner to check of the bolts were magnetic and it stuck to the magnet firmly, but not any of the new bolts. Then, I took the magnet off the rotor completely and took it for a ride and it's still reading double without it on. I disconnected the battery for 30 seconds to reset the dash (I had the speedo fail and start reading 0km/h at one point and that resolved it - known issue with Husky dash), but it didn't change anything. Can any of you guys think of anything else to check, or do I just need to get some OEM bolts and try swapping them back over?