Joined
·
408 Posts
I test the petcock by using a pair of 11" needled nose pliers to clamp the vacuum hose(middle hose coming straight down from petcock) just below the nipple on which it's attached and wiggling and pulling straight down. I don't touch the hose clamps because doing so just warps them. Reinstall the hose in the same manner.
Then remove one of the fuel hoses which are the two hoses mounted to petcock nipples right and left.
Then attach a plastic syringe to the vacuum nipple on the petcock with a rubber hose or purchase a hand vacuum pump kit from an autoparts store. Pull the syringe or vacuum pump and if petcock diaphragm is good, fuel will begin to flow from open petcock fuel nipple. Turn off petcock to stop flow.
It's best to install a long rubber hose from petcock fuel nipple to a container to catch the fuel for safety and less mess.
If you use a vacuum pump, it's not necessary to pump it hard to get fuel flow. Pulling too much vacuum could damage the petcock diaphragm.
[*edit:
Better yet, just remove the petcock vacuum hose off of the left carburetor nipple with the needle nose pliers. Insert the syringe into that hose.]
I used 150 psi for backblow through the carburetor drain nipple. I might not should have but it didn't hurt mine any. Others may have an opinion of best pressure.
Then remove one of the fuel hoses which are the two hoses mounted to petcock nipples right and left.
Then attach a plastic syringe to the vacuum nipple on the petcock with a rubber hose or purchase a hand vacuum pump kit from an autoparts store. Pull the syringe or vacuum pump and if petcock diaphragm is good, fuel will begin to flow from open petcock fuel nipple. Turn off petcock to stop flow.
It's best to install a long rubber hose from petcock fuel nipple to a container to catch the fuel for safety and less mess.
If you use a vacuum pump, it's not necessary to pump it hard to get fuel flow. Pulling too much vacuum could damage the petcock diaphragm.
[*edit:
Better yet, just remove the petcock vacuum hose off of the left carburetor nipple with the needle nose pliers. Insert the syringe into that hose.]
I used 150 psi for backblow through the carburetor drain nipple. I might not should have but it didn't hurt mine any. Others may have an opinion of best pressure.