Gas leaking out overflow tube as soon as petcock turned on fuel running out of overflow tube,running or not

SOURCE: fuel leak at bottom of petcock valve 2000 fatboy

Sounds to me like a cracked fuel line. No leaks when sitting still but add the torque of the engine turning over and the vibration and the line flexes enough to leak. If not a fuel line, the weld may be cracked where the petcock mounts to the tank or the petcock itself may be cracked. Is the petcock water trap screwed on tightly?

Gar

• 384 Answers
• Posted on Jul 23, 2009

SOURCE: HD 1979 fatboy fuel petcock valve leaking

Replace the petcock. The rubber diaphragm is ruptured. I'd also bet your fuel mileage dropped cause the ruptured diaphragm is allowing raw fuel to be sucked into the intake manifold.

jimmy nutron

• 132 Answers
• Posted on Aug 04, 2009

SOURCE: how to stop gas leak between tank and petcock 2000

there is a few things you can do use a teflon washer or tape mke shure that you get the fuel proof kind though.

SOURCE: my 2000 HD flstc is leaking gas from the petcock.

Sounds like you've got a hole in the diaphragm that's inside the petcock. To fix it, you must first drain the tanks so you can take the petcock out of them.

With the petcock out, look on the backside of it. You'll see a plate with four small screws in it. Remove the screws and a diaphragm, a small spring, and a needle valve will be behind the plate. Hold the diaphragm up to the light and slight stretch it. If you find a hole, there's your problem. Replace the diaphragm.

Now, you're one of the luckier ones. Usually these vacuum operated petcocks simply quit allowing fuel to flow to the carb. They simply won't open and they leave you stranded with a full tank of fuel but none in the carb. I suggest the purchase of a high quality manually operated petcock such as a Pingle. If you choose to go this route, you must eliminate the vacuum hose and plug it up so that you don't have a vacuum leak at the carb. The vacuum line that comes off the back of the carb has a "Y" fitting in it. The main hose "Y"'s out to feed vacuum to the VOES and the petcock. Replace the entire hose with a single hose going from the carb to the VOES thereby eliminating the hose for the petcock.

Good Luck
Steve

SOURCE: the small hole behind the

It's a diaphragm problem most likely. These things are notorious for giving problems. I always suggest people upgrade to a high quality manually operated petcock like a Pingle.

But, if you want to keep you vacuum operated petcock, you'll have to drain the tank of fuel. Get a large funnel and an empty gasoline can. Loosen the petcock with the large funnel to catch the fuel and guide it into the empty can. Unplug the fuel line and the vacuum line. Remove the petcock from the tank.

On the backside of the petcock, there's four small screws. Remove the screws and carefully take the back off the petcock. There's diaphragm, a needle and a small spring behind the plate. Hold the diaphragm up to the light and gently stretch it. Look for holes. You can get a replacement diaphragm from your local dealer.

Good Luck
Steve