'09 KLR Engine Problems
what you have highlighted is the Air Injection System (AKA AIS) a lot of people remove this. No you don't have to drain the coolant to remove it and yes you have to remove it to get to the valves. Something you might check is the petcock. it is vacuum operated and it is not unheard of to have the diaphragm that operates the petcock to wear out and leak which equals no fuel. If that is the case you have 3 options 1. fix the petcock with a rebuild kit, 2. put in a yamaha raptor petcock (non vacuum), 3. buy or build a kit to remove the diaphragm from the OE petcock.