Needle valve not closing, causes,
a) Needle valve installed upside down.
b) grit, dirt, from tank jamming needle valve open. (remove needle valve turn fuel on for a second, then put back together.
c) Wrongly adjusted 'tab' on the float, leading to needle valve not closing before overflow level reached (think dodgy ball cock on toilet system).
d) float holed and leaking petrol, thus they do not lift up high enough for the needle valve to cut the fuel off. (shake float, listen for noise)
e) needle valve corroded and not seating properly. (clean with a little Autosol from a tube, just to grind a faction off. clean VERY WELL after.
f) blocked air vent in tank. Unlikely, but on a hot day, pressure can build enough to push the float down! Loosen tank filler, listen for hissing.
g) other things I not though of!
As mentioned above, a small fuel filter is a wise investment. I found Tornado had one, and it was full of crap! I will now remember to check it every so often.
See that clear/yellow little blob under the fuel tap? Didn't even notice it was there until the other day!
