What are my screws on Dellorto?

[seaandmoor]

I've stared at my carbs and +2 manual and Dellorto websites and the more I look the more uncertain I am as there seem to be so many different discriptions for tuning, synchronising, adjusting, balancing, mixture etc and the screws are given different terms in different places and sometimes even two different terms for the same screw in the same text!
I attach a photo of my DHLA40E
Could you all agree the correct name for each of the screws which I have labelled A-F and then I'll know where to stick my screwdiver.
Many thanks

[john.p.clegg]

I'm sure Colin said something about people sticking their screwdrivers in there....

John

[alan.barker]

you also need to buy a "Carbtune" with 4 columns to balance carbs correctly without needing to remove the airbox. One of the best tools i have ever bought.
"C" is the plug to remove to attach the Carbtune adapter.
"E" is the mixture screw to adjust mixture on tickover
"A" could be the screw to balance between the 2 venturis in the same carb. So if there is a diffence you don't need to twist the carb spindle. I'm not sure because it looks like you have the European carbs with the letter E after the 40.
hope this helps
Alan B

[robertverhey]

Get thee to www.elanfactory.com.au

Technical Info

Dellorto Synchronisation and Idle Adjustment
Dellorto Carburettor Care

Robert

[alaric]

Hi. You could get 'How to build and power tune weber and dellorto DCOE, DCO/SP & DHLA carburettors' by Des Hammill. It has all the info in there and if you follow the set up procedure it should help - worked on mine. I also got the carbtune 4 column manometer.

Sean.

[seaandmoor]

Everywhere from sunny Sydney to 'sunny' Derbyshire !
Thank you for that. I've been sent some other stuff off the forum as well so I have a lot of reading to go through after which I should be much the wiser. I think I've heard of Hammill's book before and also a book for Dells by Dells themselves (or someone on their behalf) which may be on Amazon or some such site.
Thanks again
Philip Flathead!

[45bvtc]

Refer Section L. - Fuel System, pages 66 and 67 in the later Elan (1072) Workshop Manual

A) = Item 24 = Screw: this is for securing the float chamber cover to the carburettor body

B) = Item 49 = Plug: this covers (and secures) the pump jet

C) = Item 53 = Plug: this seals the pressure connection. Unless you have the kit and know what you're doing, leave it alone!

D) = Not illustrated: this adjusting screw (with locknut) was fitted to later DHLA40E Dellorto carburettors enabling the air flow to be balanced between the two chokes of one carburettor body; once set it's rarely adjusted - unless someone messes with it. Unless you have the kit and know what you're doing, leave it alone!

E) = item 47 = Screw: this is for idle mixture adjustment.
Note: on DHLA40E Dellorto carburettors this idle mixture screw is not the 2.1/2 turns out for initial setting, as were the earlier DHLA40 Dellorto carburettors, but typically 5.1/2 turns out.

I set-up an Elan S4 SE (day before yesterday) with these same DHLA40E Dellorto carburettors; so it's all very fresh in my memory. Also, you can see this is true (mixture screws well out) as the idle mixture adjustment on these DHLA40E's is near to the top of its housing.

F) = #52 = Plug: this covers the progression holes allowing for inspection

No apologies for such a long explanation, especially to the 'usual experts' who haven't bothered to attempt an explanation, yet.

PS: if you're in 'sunny Derbyshire', you're very close?

[seaandmoor]

Dear 3380 H
That is perfect - It is easy for folks to assume that I have an 'accepted' starting level of competence or knowledge which I don't on some aspects
I am learning, in fits and starts, but I'm no expert and need to prevail upon the patience and good grace of those on this forum who very kindly take the time to read my posts (probably muttering that I am a twit under their breath) and then give their advice to me, hopefully from the assumption that I know nothing so that I can follow the advice easily.
These cars are interesting to learn about and it isn't any use taking them along to a garage these days only for a pristine 'technician' to come out and say "where's socket for yer fault code reader then?"
It also gives one a sense of achievement to identify a problem (albeit with others help) and be able to effect a repair, solution or improvement.
Thank you again - including the regulars who seem to have got used to me by now and without whose chirpy suggestions I would be surrounded by a pile of bits and lost all hope and interest.
Best regards

[45bvtc]

Now that's what I call a mature, positive response, thank you.

Makes making the effort worthwhile.

Thank you again

[alaric]

Hi. I didn't know about the adjustment between the two chokes - I'll go and check mine as my rear pair are out of balance. I think the problem's the o rings on the manifold though, which have gone quite hard with age. Thanks for the tip.

Sean.

[45bvtc]

Sean, in my experience 3-types of Dellorto carburettor where fitted to Lotus Elans and Europas: we won't go into Eclat, Elite and Esprit at this stage, thank you.

Mine are as shown in the photograph, these DO NOT have the 'E' suffix so the initial idle mixture screw setting IS 2.1/2 turns out (do I need to explain this?).

In mine, the screws with which to balance the airflow between the chokes is contained within a housing, and not exposed, with locknut, as is those of 'seaandmoor'.

So, you need to check: 1) your O-rings and 2) your carburettors.

Regards...

[45bvtc]

Please excuse the state, but this is an early Dellorto (ex-1972 Europa Twin Cam (mine)) from my store (shed) bin.

The main differences, externally, between this and my previous photographs are: 1) that the idle mixture screws and springs (see Arrows) are exposed, and 2) there is no (between choke) balance adjustment screw.

This should be considered with my previous posts relating to the 3-types of Dellorto carburettors fitted between 1971 and 1975.

For my sins and age I was about at that time?

Hope this helps?