Tim Downie explained on 31/05/2008 :
Harry Bloomfield wrote:
Tim Downie laid this down on his screen :
My McCulloch two-stroke strimmer has started leaking fuel though
the breather in the filler cap.

It seems to have started whilst it was in storage over winter but I
didn't really twig to the problem until I had to top up its tank
and found it dripping continuously through the vent plug.

I guess I just need a new cap but any ideas as to why it should
have started leaking in the first place? There are no cracks and
the O-ring is intact. The fuel is definitely coming through the
central breather plug. Tim

If this is while it is in use....

No. I happens if I just tip the strimmer so that the fuel covers the filler
cap.

I had a quick google for McCulloch spares but could find filler caps. Anyone
know of a site selling filler caps?

Tim

In that case I would suspect the filler itself is not sealing properly,
I think the cap needs to seal to enable the breather to work as
designed. We had a plastic filler cap on a plastic tank (lawnmower).
The cap would tighten up, but binding on its threads due to distortion,
it would not screw down all the way to the O ring seal.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk