Kawasaki Vulcan 500 dying problems - 2007, 2008 and maybe earlier.
After studying the owner’s manual and the service manual I removed the seat, speedometer console and removed bolts holding the tank to the frame. Without removing fuel and vacuum hoses I could get the tank out of the way for a serious inspection.
Left carburetor vacuum hose is supposed to operate the vacuum fuel valve (petcock). This is a safety devise probably required by DOT or some other agency. It’s a take-off on requirements for racing equipment today. If engine stops running fuel stops flowing from the tank. So, in ON or RES position this device is a vacuum controlled on-off valve. In PRI position it is a manually controlled valve just like motorcycles have had for 100 years. The Kawasaki manual nomenclature suggest Danger is lurking if valve is left in the PRI position and the bike were to lay over on its side. Fuel would leak from the carburetor. I wonder if motorcyclist knew about this during the past 100 years.
I believe I now will consider that:
ON really means mostly ON, fuel mostly flowing if motor running, means OFF if motor not running.
RES really means mostly RES, fuel mostly flowing if motor running, means OFF if motor not running.
PRI means any fuel in the tank will for really sure flow to the carburetors.
If the bike attains it’s natural position, horizontal laying on its side, fuel may leak out of the float type carburetors and I’m responsible for turning the valve to ON to stop the fuel flow. Remember, its kinda like clicking START to turn a computer OFF?
Other:
The hose you see attached to the right side of the fuel valve is the only fuel route to the carburetors.
The vacuum hose attached to the right side carburetor provides vacuum for the fuel vapor control system.
Tank is supposed to hold 4 gallons. Use the trip odometer and remember the old Harley Davidson rider expression - DPG – “don’t pass gas.”
Will the VN500 go 200 miles on a tank? Maybe. 250?
Bob Hutchinson
Classic Motorcycle Association
2008@paq.net