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[Wanted: Parts] Solex 34 pict 3 carb wanted

Tim

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yes i measured them with a digital vernier calipers, thats the ID at the base flange.

According to the technical spec I,ve seen.....28Pict has a 22.5 venturi, 30 Pict has a 24 venturi, 31 Pict has a 25.5 venturi, and a 34 Pict has a 26 venturi.

Maybe your dimension is the inside diameter of the carb body.

I have one, but I cant put me mitts on it at the moment.

tim
 

Aidan

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July 10, 2009
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According to the technical spec I,ve seen.....28Pict has a 22.5 venturi, 30 Pict has a 24 venturi, 31 Pict has a 25.5 venturi, and a 34 Pict has a 26 venturi.

Maybe your dimension is the inside diameter of the carb body.

I have one, but I cant put me mitts on it at the moment.

tim

The gasket for the 34 has an internal diameter of 34mm so that corresponds with 411 Guy's measurement. I'm guessing that it narrows further up (for velocity?) and the smaller measurements are at the narrowest point
 

Tim

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Maybe increase the idle jet one size, it might sort it.


1971-1974 34PICT/3 Carburetor
Venturi: 26mmPower (Auxiliary) Fuel Jet: 60
Main Jet: X127.5Float Needle Valve Diameter: 1.5mm
Air Correction Jet: 75Z (80Z for Ghia)Float Weight: 8.5 grams
Pilot (Idle) Jet: 55Accelerator Pump Feed: 1.3 - 1.6cc/stroke
Pilot Jet Air Bleed: 147.5Fuel Pump Delivery Pressure (max): 3 - 5 psi
Accelerator Pump Jet: 50Delivery Capacity (min): 400cc/min @ 4000 rpm
[FONT=Verdana, Arial, Helvetica, sans-serif][/FONT]
 

JustinOval

Super Super Super
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November 9, 2006
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Choke without vent might be 34mm, I have a set of 32mm vents here for 40mm DRLA's which actually measure 41.5mm (OD).
 

rascal1

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January 12, 2007
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Marino, Dublin
Aidan
I have a tin with some a 34 in bits and a H30/31 in the same condition.You are welcome to take the butterflys' or any other part for that matter.
My office is in Kildare town and there is always someone here between 8.30 and 5.0.
I can leave here if you can collect.What you don't want just leave back.The size of the hole in the butterfly is the only difference between a dvda and an svda. Not sure of the sizes
but the svda is the one with the smaller hole..
 

Aidan

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July 10, 2009
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Aidan
I have a tin with some a 34 in bits and a H30/31 in the same condition.You are welcome to take the butterflys' or any other part for that matter.
My office is in Kildare town and there is always someone here between 8.30 and 5.0.
I can leave here if you can collect.What you don't want just leave back.The size of the hole in the butterfly is the only difference between a dvda and an svda. Not sure of the sizes
but the svda is the one with the smaller hole..

@Rascal1 - That's brilliant - thanks. The Samba thread mentioned the SVDA hole as being 1/8" and the DVDA hole being 5/32" which doesn't sound that significant but I'll do a bit more research before making any changes. I'll PM you re collection.

@Tim - thanks for the sizes - and the suggestion re idle jet size. It'd definitely offset the amount of air being dragged though the butterfly although it might still be hard to get the ratio right. I'll start with the butterfly and experiment with the jet after although I'm optimistic that the butterfly will make a big difference.
 

Aidan

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As this has turned into a kind of Workshop thread I thought it might be useful to post results as someone may well be searching around the topic in the future..

After trying everything else I could think of, I ended up pop riveting the hole in the butterfly and removing the pin. It really makes a difference - I got a nice stable idle and turning the volume control screw actually makes a difference now. I'm not entirely convinced that its getting enough vacuum early enough as it feels a little flat under acceleration at 2000 rpm (the advance drillings on the DVDA carbs are different to the SVDA) but its driving very nicely now and I'm happy enough.

FWIW I also measured and increased the output of the accelerator pump to spec to try and overcome the flatness. Valve clearances are to spec. I'm running a 60 idle jet and timing is correct at max 30 BTDC vacuum disconnected + plugged and 40 BTDC vac and centrifugal on a new Bosch SVDA (034) distributor so I reckon that the vacuum signal from the carb is the culprit. I don't have full degree markings on my pulley so I can't say for sure where the vacuum advance really kicks in.
 
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Tim

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Flat acceleration at about 2000 , might also signal an undersized power jet. Are you happy
that its jetted correctly.

Good to know the butterfly tweak does the job.
 

Aidan

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Thanks Tim. When you say power jet do you mean auxiliary jet? I understood that it kicked in at the highest revs and wouldn't impact on lower speeds? My aux jet is 47 (Haynes lists 42.5 as does Bentley). There is a power jet listed in the specs but its pressed into a drilling from what I can see so I'd imagine that its a factory fitment - can't imagine anyone going to the trouble of making one smaller. I'm still learning these Solex carbs so any more info would be much appreciated.
 

Tim

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Power jet is listed as 60 for the 34 Pict 3.

solex_68to74.jpg
26 or 27 on this I think.
 
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Aidan

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Thats the one Tim - I think that the type 2/type 1 specs are different though - 42 is the listed type 2 size in both manuals that I have and I'm running a bigger jet than that at the moment.
 

Tim

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After the tweak you have performed on the butterfly, thus increasing the vacuum,
its recommended that you also increase the main jet one size.
 

Aidan

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Thanks again Tim - I've gone up two main jet sizes but as it was running lean anyway it looks like I'm there or thereabouts. I'll put up a couple of hundred miles and have a look at the plugs. Its definitely much improved overall.
 

Tim

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When you increased the main jet size, did you also change the air correction jet
to match. When you change one, you normally change the other as well.
But considering your butterfly tweak, you now have a carb that is not stock
setting, you will probably have to play a bit with different jet sizes, to get it spot on.

Nice to know its a big improvement on what it was......good stuff.
 
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