Help ! what tool (sparkplug socket do i need?
 

i want to pull the secondary plugs on the bike, but can't get a standard 18mm

does anyone know the diameter of the tightest point is, so i can find a thin socket to fit???

I gave up trying to find a thin-walled socket and just used the spark plug tool that came with the tool kit on the bike, under the rear seat. I was worried that I wouldn't be able to get the torque I needed to pull the plugs, but those sneaky germans knew what they were doing when they made that thing...