How do you test for a bad petcock?
If fuel comes out when you suck (create vacuum) on the vacuum hose on the “on & reserve” setting then the petcock is operating properly! Fuel should flow on the “prime” setting with no vacuum applied to the hose. If fuel is flowing ALL the time with no vacuum applied then you have a bad vacuum diaphragm.
What does a petcock do on a Harley Davidson?
A Harley-Davidson fuel petcock is a valve responsible for controlling the flow of gasoline from your gas tank to your carburetor. Whether you’re replacing a failing fuel valve or building the bike of your dreams, J&P Cycles has you covered with a full selection of Harley petcocks.
How do you remove fuel from a petcock?
Open the petcock putting it in the reserve position (to remove all the fuel). Then you have to apply a gentle vacuum to the vacuum port on the petcock. How you do this is up to you.
How do you clean a Harley Davidson petcock?
Open the petcock putting it in the reserve position (to remove all the fuel). Then you have to apply a gentle vacuum to the vacuum port on the petcock. How you do this is up to you. I’ve attached a short rubber hose to a syringe and then to the petcock at which I draw a slight vacuum.
When to get rid of the vacuum petcock?
Most times when they fail the engine just quits from lack of fuel. Glider has it right, get rid of the vacuum petcock and go for a Pingle. I figured if the diaphram were torn it would close off fuel supply. I was thinking that it would be possible for fuel to flow through the vacuum line to the carb adding extra fuel to the mix.
A Harley-Davidson fuel petcock is a valve responsible for controlling the flow of gasoline from your gas tank to your carburetor. Whether you’re replacing a failing fuel valve or building the bike of your dreams, J&P Cycles has you covered with a full selection of Harley petcocks.
What to do if there is no fuel flow from the petcock?
If you know there is no fuel flow from the petcock with the engine not running, disconnect the fuel line from the petcock (you could remove it from the carb but working from the petcock is probably easier AND you don’t have to mess with the plastic carb inlet elbow which tends to break very easily). Then disconnect the vacuum line from the petcock.
Open the petcock putting it in the reserve position (to remove all the fuel). Then you have to apply a gentle vacuum to the vacuum port on the petcock. How you do this is up to you. I’ve attached a short rubber hose to a syringe and then to the petcock at which I draw a slight vacuum.
Most times when they fail the engine just quits from lack of fuel. Glider has it right, get rid of the vacuum petcock and go for a Pingle. I figured if the diaphram were torn it would close off fuel supply. I was thinking that it would be possible for fuel to flow through the vacuum line to the carb adding extra fuel to the mix.