HS needle valves - fibre washer?

[floormanager]

Interested to know whether the needle valve should have a fibre washer as it screws into the float chamber lid? Can't see one on the SU replacement valve or drawings,

SU needle.JPG

yet other types of valve sold show a fibre washer?

other needles.JPG

[111Robin]

Never had a washer on the standard valve, certainly I've never seen one and wouldn't see any point. In theory if pump pressure was high enough and the valve closed then fuel could leak by the thread but it would just drip into the float chamber by such a small volume as not to cause a problem. If I sit with ignition on while working on an electrical fault the pump will click once every few minutes with no external leakage so it could be passing the thread but under normal driving would never be noticed.

[Peter Laidler]

I think that the fibre washer is being over cautious or maybe it is to prevent the brass valve from digging into the soft mazak alloy housing and act as a locking medium between the two as it expands. That said, if I was given the fibre washer, I'd use it!

[floormanager]

I think that the fibre washer is being over cautious or maybe it is to prevent the brass valve from digging into the soft mazak alloy housing and act as a locking medium between the two as it expands. That said, if I was given the fibre washer, I'd use it!

I think so too. I've ordered some. The next time the needle valves are out (if I remember where I put the washers) I'll fit one under each, although they do not appear to be necessary.
Paul

[111Robin]

The washer will affect the position of the valve seat, hence the float height when closed won't it ?. Depends on how much you compress the washer but it will result in a different level of fuel in the bowl.

[jay weinstein]

The washers were used to set the float level on the one piece (all plastic)
floats. I think they came with three different thicknesses and you used as
many as necessary.

[IslandBlue]

The washers were used to set the float level on the one piece (all plastic)
floats. I think they came with three different thicknesses and you used as
many as necessary.

This seems logical, I have used a washer in the past in this way and it stopped the float chamber overflowing.

[floormanager]

The washers were used to set the float level on the one piece (all plastic)
floats. I think they came with three different thicknesses and you used as
many as necessary.

This seems logical, I have used a washer in the past in this way and it stopped the float chamber overflowing.

Interesting in light of the new floats are adjustable once again.

[Peter Laidler]

Er......., it will of course........, but quite how much adjustment a 1mm(>) thick crushable washer will alter the jet, even as a ratio, isn't something to lose any sleep about

[IslandBlue]

The washers were used to set the float level on the one piece (all plastic)
floats. I think they came with three different thicknesses and you used as
many as necessary.

This seems logical, I have used a washer in the past in this way and it stopped the float chamber overflowing.

Interesting in light of the new floats are adjustable once again.

I hadn't seen that, do you mean the "stayup" float?

[bwaminispeed]

Actually, 1mm makes quite a big difference, the fulcrum point is very close to the needle center, so, the ratio is quite large......

[floormanager]

indeed

[Andrew1967]

Just fitted these to my carbs and there were no fibre washers in the kit. Nor were there any old ones when I stripped the carbs.