Fuel petcock trouble

[RContino]

Just installed my Kings 49cc kit... so far so good, but my fuel petcock (tank switch) seems to be faulty. When the fuel line tube is not connected and petcock is open the fuel slowly trickles out. When the fuel line tube is connected and petcock is open, nothing comes through at all. The fuel filter is clean and petcock threads don't seem stripped.

Does the fuel line need to be completely vertical - with the tank directly above the carb? Seems so simple, am I missing something here?

 

[bairdco]

do you have an inline filter? if you do, is it upside down?

or the tank might not be venting properly. if you leave the gas cap off does fuel come out the hose?

other than that, it's a mystery to me.

the tank doesn't have to be directly above the carb, but it does need to be higher than it, as it's gravity fed.

 

[RContino]

I'm not really sure if it's inline, but I attached a picture of it.

I tried it with the gas cap off... no dice.

It's also leaking a bit by the threads - maybe it is stripped, and if it is could this potentially be the cause?

 

[bairdco]

that's a tank filter attached to the petcock. it'll unscrew, but if fuel flows out of the petcock, it should be fine.

i don't understand why it would flow from the petcock, but not with the hose attached, unless the hose is plugged up.

as for the leaks, they'll do that. you can get some teflon tape which might help, or a copper sealing washer instead of the fiber, or when it's really clean and dry try some silicone on the threads.

unless it is stripped, then i think you could tap it for a pipe thread fitting (those tanks are straight threaded) but i never had to do that.

 

[27t]

Had the same problem with my new Hua Sheng 4 stroke kit; fuel just dribbling from the petcock valve. I found the valve discharge hole had not been drilled all the way through to the center of the valve.