Weber Needle Valves

[Stuart+2]

I am just doing an overhaul of the 40DCOEs with a kit from QED.
I noticed that the new needle valves are spring loaded whereas the ones in the Carbs now are not.
I am concerned that the float settings may be incorrect given the additional (marginal) downforce from the needle valve springs.
Can anyone advise please?

Many thanks

[rgh0]

You need to set the actual fuel level to 25mm +/- 0.5mm below the top surface of the block the carb jets screw into. You need to do this by direct measurement of the fuel level. The setting methods provided by Lotus in the workshop manual and Weber in the instructions that come with the rebuild kit are far to approximate and prone to error regardless of whether you are talking about the old or new style needle valves.

cheers
Rohan.

[Robbie693]

You need to set the actual fuel level to 25mm +/- 0.5mm below the top surface of the block the carb jets screw into

Hi Rohan,

Is this the same height as the top of the carb body?

Robbie

[rgh0]

If you take the small round top cover with the butterfly nut off the carb, underneath is a flat surface with the 2 main jets and 2 idle jets assemblies screwed into it. Measure the fuel level from this flat surface height down.

The easy way to meaure is an "optical gauge" as developed by Elan owner and weber specialist Keith on the Yahoo sidedraft central forum. An acrylic rod with the ends polished can be lowered into the hole when you remove one of the main jets. Looking down the rod you will see the rod end go dark when it touches the fuel level. A slip ring on the rod that rests on the top surface enables you to measure the length of rod down the hole when it touched te fuel surface. The end stem of a a set of vernier calipers can do a similar job with more try and error attempts to read when the end just gets wetted by the fuel.

cheers
Rohan

[alan]

hi rohan,
is it possible to do something similar with dellorto carbs ? what do you think ?
AlanB

[rgh0]

Yes should be possible to do same with Delortos - you just need to know the correct dimension - I have never seen it quoted anywhere

cheers
Rohan

[Stuart+2]

Thanks Rohan

There were no instructions at all with the rebuild kit so your advice is appreciated!

Cheers

[Robbie693]

Thanks Rohan, I had assumed this would apply to dellorto's aswell, never thought to ask if there would be a difference so thanks Alan too for asking!

Robbie

[alan]

hi, i have just found this website to set fuel level on dellortos like the webbers http://www.sideways-technologies.co.uk/ ... pl?b-Del1/. for me it seems a good idea
AlanB

[Keith Scarfe]

This is the thread I have been looking for. Adding a comment from me so I can find it again easily.
This is the best method for setting fuel level / float height in a weber carb.