Since I'm not 100% sure my bike is consuming coolant, I glued a little section of a plastic metric ruler to the reservoir bottle with contact cement. Not the cleanest installation, does not look factory, but it works for me. If the contact cement melts the reservoir, I've got a brand new one in the box from the PO sitting in my garage.
Cheap, effective, accurate. I just hope its stays glued with the normal V-Twin vibration.
