Check Valve at Fuel Tank

[Shermanator31660]

I"m still trying to figure out my Yammy fuel starvation problem. Replaced the primer bulbs, they work fine, re-routed and tried different fuel line hookups but, I still can't get the bulb to prime up nice and tight. I found through my trial and error procedures that there is a one way check valve in the brass fitting right where the fuel line connects to the gas tank. The ball is nice and loose, it holds pressure when you put a vacuum on it, is it possible that the spring in this assembly has gotten weak and is not doing its job?? You can pump on the primer bulb all day and it won't firm up, all fittings have been double checked, no gas leaks so pretty much down to this one way valve thingy.........Sherm

 

[N1NE1]

Is the tank vent clear?Fuel water separator filter clogged? The anti siphon valve your talking about can be removed and replaced with a regular barbed fitting ..no springs or ball..You can get one at home depot or lowes.

 

[N1NE1]

Also on the fitting where that barbed fitting screws into,The pickup tube coming from inside tank has a metal screen filter on the end of it.The whole thing should turn out of the tank

 

[Shermanator31660]

I did get rid of the check valve even though it "seemed" to be functioning properly. From what I've read the primer bulb does basically the same thing in preventing a back flow of fuel. I also put in a new fuel/water filter even though the previous one was only a couple months old. Screen in the tank is clean as is the vent on the gas cap. Took it out, it "seemed" to be OK, I checked the exit fuel pressure at both lift pumps and they were both off the gauge so they seem to be working fine. A couple more outings and we'll see if I found the Gremlin or not, thanks for the reply.........Sherm

 

[Doh]

poke the engine side of the fuel line with a pen or something to equalize the pressure on both side of the ball. If the ball is coming back up to fullsize, you can pinch the tank side hose while pressing on the ball, engine side of the hose while releasing the ball.