wavy

Got one of E-bay to fit my 03 650 SM but the magnet on the disc that activates the speedo dont pass near enough to the sensor to activate it. what have other people done to over come this?

when rebuilding my engine i noted that the barrel/spigot/lining or whatever; had ripples at the top and bottom but badly at the top? i trust this a nikasil lining these barrels have? only i had about 10 barrels on the ducati F2 i raced and there was NEVER a mark or a notch! it was air...