Hello Sunnyday thanks for that. That's what I hope will solve it too, so it's good to know that it worked for you!

I've just got the new aftermarket valve seats + needles in and set the float heights.

Just took the old two rubber parts and the spring out of the tap and replaced with new bits from Rick O. Now I have the opposite problem than before, cos I can't get any fuel to flow through the tap. I even attached a hoover to the vacuum hose and put the tap on RES, still nothing comes out

[[EDIT]] I did it wrong when I put it back together, I had the vacuum hose connection plate in the middle and the drain/breather on the outside, so it couldn't have worked and that's why it didn't. D'oh!

http://www.akhara.com/nc30/fueltapmod/ pictures make it clear what the right order is