Petcock Diaphragm Cover

Hi I am just refurbing two KZ750 Ltd petcocks (we call them fuel taps here in the UK). I have bought the necessary repair kits with O rings and diaphragm. Does the diaphragm cover (the part which has TAIYOGIKEN stamped on it) have a one way valve in the vacuum tube. On one of mine I can suck air through the brass tube but can't blow air through. On the other I can suck and blow either way. Also does it matter on re-assembly which way the vacuum stub faces?
Tommotbird

the one that you can suck AND blow is missing a tiny bakelight/plastic piece inside the brass vacuum spigot port.

downward is a good way for the spigot to point.
however if you like it can go forward or backward according to the locator pins.

trippivot wrote:

the one that you can suck AND blow is missing a tiny bakelight/plastic piece inside the brass vacuum spigot port.

Hey trippivot...I think I might have a picture of what you are talking about on this site here .

If it is the part you are talking about, the last two pictures are probably the most relevant.

Yes that would seem to make sense. How important is the little bakelite/plastic part & is the petcock going to function OK without it. It seems to be quite difficult to unscrew the brass spigot without doing it some real damage.

Tommotbird wrote:

Yes that would seem to make sense. How important is the little bakelite/plastic part & is the petcock going to function OK without it. It seems to be quite difficult to unscrew the brass spigot without doing it some real damage.

I don't know how important it is because I put mine back in so I can't say if it would work without it.

However, I got mine out without any damage by using a correctly sized small wrench. I wouldn't recommend it unless you have the small wrench though.

EDIT: BTW, after I rebuilt mine and had it re-connected to the gas tank, I tried moving its position from "on" to "prime" but it wouldn't budge. At first I thought I had messed something up. However, I was able to 'force' it to turn with some extra strength and since then it has not been an issue at all. Just wanted to add that in case you run into the same problem after the rebuild.

Post edited by: Little B, at: 2007/10/02 00:35