Lancia Beta Forum

Made the most of the pleasant although still cool sunny weather this afternoon for a spot of tinkering and a couple of "essential" road miles in preparation for a return to a post lockdown world.

Over last couple of months have completed various works including -

New brake pipes, master cylinder, rear load sensor, new pads and discs front and rear.
New front and middle exhaust sections + machining of warped flange face on exhaust manifold
Carb freshen up, clean, and re-jet

Apart from a very slight vibration of the middle exhaust box against body during warm-up (I will adjust ) then car driving beautifully. The new discs and pads although not fully bedded in yet seem to have made a big difference (I wasn't totally sure about EBC - but seem fine).  Re-jetting carb has been revelatory!

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Andrew,

That's a very satisfying list to tick off.

Glad you got the carb sorted.
Car looks superb. Is that the flat greyish blue colour?
Happy days

Nigel

Looking good Andrew. Itching to get mine on the road again too. Am behaving myself for now.

Best wishes

Mark

Have fun!

By the way, this notion that journeys have to be essential is a huge fib put about by Government websites and the media.  In England at least, the rule has always been and still is that a journey must be reasonable, not essential.

Andrew, you mentioned 'Re-jetting' your carb. How and where did you find the appropriate new jets? I have a decent second hand carb awaiting attention. Standard DATR Weber for my 77 Coupe. It requires a professional clean and refurb, and I reckon new jets would be sensible. Cheers, Jono.

Just bought a couple of idle & main jets very slightly larger than standard + slightly smaller air corrector caps.  No magic formula or rolling road determination but a road test based trial and error exercise to arrive at something more generous than standard that seems to make a positive difference!

Bought my spares from here

https://www.dellorto.co.uk/product-category/weber-carburettors-parts/carburettor-parts-weber-carburettors-parts/dmtl-parts/ (https://www.dellorto.co.uk/product-category/weber-carburettors-parts/carburettor-parts-weber-carburettors-parts/dmtl-parts/)

Update:  you can now go out for recreation as well as exercise.  So you need not be driving your Beta to the shops or whatever, you can just be driving out for fun.  Having said that, driving your Beta to the shops is a splendid idea.

Similar question about the jets. My carb is on my workbench having had a good clean and refurb, however identifying jets is still eluding me. How do you know what size you had and hence know possible sizes you could go to?

The sizes etc. are stamped on the jets in extremely small font. Not visible to the over 30s without a good magnifying glass I have found......

Hi John

On the air correctors (larger of the two) the size is stamped on the face which is uppermost, probably will read 170 or 210 or 240. The smaller actual jet it is stamped in very hard to read halfway down the tube. According to Haynes should be 1.5 and 1.2, but I can see 80 and 50 on mine, so not sure exactly how to interpret them yet.....

Peter

Hmm . . . there are 4 brass screw threads and I can't recall which is emulsion tube, primary, corrector etc. however 180 stamped at one end of one, F27 on the side of another and 50 on the side of the remaining 2..

So, at least your 50 is consistent with another 34 DAT. Just be aware my carb was replaced with a new unit that was an original fit for a Strada 105TC

Hi John

F27 is the type of emulsion tube the top of the tube has the air corrector pushed on (numbered on top) the bottom of the tube has the main fuel jet pushed in (numbered on the side). Each Emulsion tube feeds one Choke and supplies the main circuit fueling and cross over fueling called progression as you move from the idle jets. There are 2 idle jet again 1 for each choke. Whether you can split the main jet and air corrector on the idle jets depends on the carb type. On DCOEs they are in FXX sizing like F5 F55 F9 F6 but the sequence is not logical for lean to rich.
You also get Pump jets to cover acceleration flat spots. These are L shaped tubes at the top of the chokes. They are fed by a diaphragm pump on the side of the carb and have a ball valve inside which can stick and the diaphragm can fail.

Unfortunately drilling jets is common at rolling roads and they do not always re-label the jets.

Carbs are precision items so even carbon and gum on the jets and fine particles in the float chamber play havoc with the setup.
 
Float level and auto choke position have to be precisely set or trouble follows. Fuel too high on the emulsion tube changes the Air Fuel ratio at a given speed/load range. Auto choke with crud in the water ways does not move when it should leading to annoying stalls.

And this is why I like FI!

Eric   

       

The only problem with the DATR is that it has proved impossible to find a float level measurement. I tried and still have not come up with anything yet!

Peter

On the DATR you have an air corrector/emulsion tube and separate jet for each choke. As Eric says the emulsion tube has two parts to it, the top part which is a screwed section which is marked on top and the main tube part which is marked on the side. The jet is also a plug in to a simple screw top with the jet size on the side.

Here is photo of the emulsion tube on the left and the jet (split into two) on the right.

Peter

Same here. And I hate not knowing such a crucial specification.

Peter, there are 4 jets, an idle and main jet for each choke - idle jets which are single piece items (including a fixed air corrector hole) fitting to the end of threaded holders. These are responsible for fuelling of each choke for first 40% or so of throttle plate opening. Beyond this then main jets come into play. The main jets are small push on/off items at the bottom of the emulsion tubes with the threaded air corrector caps pushing onto the other ends of the tubes.

Float setting - just go for as near as possible to perfectly level (parallel) to top plate - without pushing spring loaded bulb on end of needle valve. Should be around 7.5 - 8 mm I think.

Hi

I stand corrected, I did not realise the end of the emulsion tube end was removable as well!

Thanks for that info on the float level. I compared my refurbished one with an original and it is pretty similar.

Peter

I might be your best friend soon .  .. (or not!)

Hi John

You get 10 out of 10 for that info. Not sure where you found it as the DATR version is different for the Beta, but I would imagine the float setting is the same. You obviously have to interpret the translation I think,  it pretty obvious what is going on.

Many thanks for that, suspect a few folk will be interested in it as I have seen it asked before.

Peter

And one little tip for old eyes in case you didn’t already know. There is a magnifier app available which I use on my iPhone and it is very useful. Apologies if teaching grandmothers etc.

Near impossible to hold the carb 100% perpendicular so I took the mm-accurate settings with a "margin of error" . .

Had a look at this today and sadly not that applicable to the above drawing. The main reason is the float is not a uniform round object, it is a complicated shape and hence not convinced the above is the correct setup as hard to judge where to measure to.....

Peter

Peter,

Just try to get the top flat surface of each float half parallel with the carb top cover face and adjusting to maintain gap between 7.5 and 8 mm before gasket.  Gasket will be just over 0.5mm, say 0.5mm when top screwed down.

If the spring loaded damper ball in the needle valve is not too tired then this should support the float even if carb top cover fully inverted.  Before fitting gasket and re-assembly I just concentrate on getting each float half set similarly with each float top surface parallel with carb top cover face.  I do this by eye and when I have measured it comes out at between 7 and 8mm (i.e. before gasket)

Have just split my spare carb - working OK a few weeks ago and measured float height  ......

Where did that come from?
Finally a float level specification in print.

Bravissimo

Hi

Thanks, I will look at the floats I have which I think are a different shape, hence my comment. Yours are flat on top which makes for easy measurement.

Peter

Just to add to the debate then see that Eurocarb quote float height of 7.75mm/8.25mm with gasket

https://www.dellorto.co.uk/shop/weber-carburettors-parts/carburettor-parts-weber-carburettors-parts/dmtl-parts/dmtl-float/ (https://www.dellorto.co.uk/shop/weber-carburettors-parts/carburettor-parts-weber-carburettors-parts/dmtl-parts/dmtl-float/)

(New Floats available elsewhere for considerably less)

It came with a refurbishment kit so I think I need to give credit to Ricambio who supplied it, and answered a few rookie questions from me. Good service and happy to recommend

I checked on my float and sure enough it is a replacement I had as part of a kit and it is different to the Weber original which I also still have. the Weber is flat on top, my float has a small bulge on it, approx 3-4mm high. I therefore measured to the main body and set accordingly. So far with limited test possible it is working ok.

Peter