S.U Carbs leaking

[BATES]

Hi, Just started after winter lay up.the carb nearest the bulk head is leaking fuel to the point where it puddels on the ground ,the middle one is leaking a bit .Last six years I have not had a problem.They are not flooding .Looking at the manual I suspect the seal of the jet has failed ,is this a common problem ,Thank for your help Gordon

[Heuer]

The SU bowls have overflow pipes - is the fuel coming out of those? The pump sends fuel to the bowls on demand from the floats so if the floats are sticking or leaky they will not rise and cut off the supply. Suggest you check the bowls and floats first. Very good SU guide in the Knowledge Base: http://etypeuk.com/forum/viewtopic.php?t=1664

[christopher storey]

If the fuel is going through an overflow pipe, it is a sure sign of the problem David has identified. I find that a sharp tap on the float chamber and/or its lid with the wooden handle of a screwdriver is often sufficient to dislodge a stuck needle valve. otherwise, as he says, you need to remove the float chamber lid. Be sure a. not to lose or damage the gasket and b. to assemble the lid fixings in the right order, which from the top is

Nut , plain washer , overflow pipe , slotted washer , lid . The slotted washer is most important, as it equalizes atmospheric pressure within the chamber as fuel is used or replenished

[BATES]

Hi ,I will take another look next week end ,the fuel seems to becoming from the diaphram seal at the bottom of the carb were the four nuts are .I will let you know how I get on .Thanks Gordon.

[BATES]

Hi I tapped the carbs one has stopped complety the bad one has almost stopped Thanks for you help Gordon.

[alangordonman]

If one is still slightly weeping I suggest you check the float levels and you may find that the one still leaking is set too high. Alan