Lotus Elan

Weber Needle Valves

PostPost by: Stuart+2 » Mon Mar 29, 2010 7:28 am

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
Stuart - Sydney
1968 +2 50/1035
Stuart+2
Second Gear
Second Gear
 
Posts: 118
Joined: 18 Nov 2006
Location: Sydney, Australia

PostPost by: rgh0 » Mon Mar 29, 2010 8:51 am

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.
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7163
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: Robbie693 » Mon Mar 29, 2010 9:16 am

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
User avatar
Robbie693
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1614
Joined: 08 Oct 2003
Location: UK

PostPost by: rgh0 » Mon Mar 29, 2010 11:15 am

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
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7163
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: alan » Mon Mar 29, 2010 4:49 pm

hi rohan,
is it possible to do something similar with dellorto carbs ? what do you think ?
AlanB
Alan.B
alan
Third Gear
Third Gear
 
Posts: 312
Joined: 29 Jan 2007
Location: France Morbihan

PostPost by: rgh0 » Mon Mar 29, 2010 11:53 pm

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
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7163
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: Stuart+2 » Tue Mar 30, 2010 4:43 am

Thanks Rohan

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

Cheers
Stuart - Sydney
1968 +2 50/1035
Stuart+2
Second Gear
Second Gear
 
Posts: 118
Joined: 18 Nov 2006
Location: Sydney, Australia

PostPost by: Robbie693 » Tue Mar 30, 2010 9:49 am

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

Robbie
User avatar
Robbie693
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1614
Joined: 08 Oct 2003
Location: UK

PostPost by: alan » Tue Mar 30, 2010 10:02 am

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
Alan.B
alan
Third Gear
Third Gear
 
Posts: 312
Joined: 29 Jan 2007
Location: France Morbihan

PostPost by: Keith Scarfe » Tue May 21, 2019 12:34 pm

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.
Keith Scarfe
Third Gear
Third Gear
 
Posts: 237
Joined: 10 May 2004
Location: Suffolk, UK

Total Online:

Users browsing this forum: No registered users and 2 guests