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Ataristyle Samba Member
Joined: February 11, 2008 Posts: 135 Location: McHenry, IL
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Posted: Mon Apr 07, 2008 1:56 pm Post subject: What is stock 34 Pict 3 JETS? |
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Sorry to start a new topic if I am. Simply put what is the stock jets in a 34 pict 3 carb? I purchased one from MOFOCO and installed it. Runs good. Its a Bug motor I have in a BUS. Reason I ask here is bus guys say 125 main, 60 air corrector & 57.5 pilot jet is the correct jetting (according to the Bentley Manual) in a BUS carb. Basically a little more rich going down the road than a bug. Is this a myth? Please someone clarify if they can cause I thought all 34 carbs are created equal. |
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Randy in Maine Samba Member

Joined: August 03, 2003 Posts: 34890 Location: The Beach
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Ataristyle Samba Member
Joined: February 11, 2008 Posts: 135 Location: McHenry, IL
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PierreDeKat Samba Member

Joined: May 06, 2005 Posts: 694 Location: Puerto Vallarta
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Posted: Mon Apr 07, 2008 7:08 pm Post subject: |
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Sounds a little lean to me.
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1971-1974 34PICT/3 Carburetor
Venturi: 26mm
Power (Auxiliary) Fuel Jet: 60
Main Jet: X127.5
Float Needle Valve Diameter: 1.5mm
Air Correction Jet: 75Z (80Z for Ghia)
Float Weight: 8.5 grams
Pilot (Idle) Jet: 55
Accelerator Pump Feed: 1.3 - 1.6cc/stroke
Pilot Jet Air Bleed: 147.5
Fuel Pump Delivery Pressure (max): 3 - 5 psi
Accelerator Pump Jet: 50
Delivery Capacity (min): 400cc/min @ 4000 rpm
The jets in Dave's 34 PICT/3 carburetor are -
* Main jet - X130
* Idle jet - 55
* Air correction jet - 80Z |
I have always heard that the minimum recommended main jet is 127.5. That's considered by some to be borderline and can cause the engine to run just a smidgen warm due to less evaporative cooling.
It makes for some pretty decent gas mileage, so that's what I have been running. But I do have to watch my temperature in the summer months.
I think you'd probably want to contact MOFOCO to see what kind of jets they're sending their carbs out with and then go from there. But I think a minimum of 130 would probably be better for your situation. _________________ 68 Beetle
And keeping my eye out for a Kombi or a Microbus!  |
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Ataristyle Samba Member
Joined: February 11, 2008 Posts: 135 Location: McHenry, IL
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Posted: Mon Apr 07, 2008 7:53 pm Post subject: |
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I sent MOFOCO an email. If I don't hear from him by lunch time I'll just give a jingle over there. So I wonder why wouldn't VW just leave the 34 style carb with standard jets across the board. I mean I can somewhat understand them changing a dist and matching it...but when it comes to a BUG motor or a BUS motor...Whats the difference...they should be the same jetting for either.
Previous to the 34 I had a 30/31 with adapter on the 1600DP and that was running very lean, because it would stumble alot if not warmed up for 5-10 mins in 30 degree weather. |
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PierreDeKat Samba Member

Joined: May 06, 2005 Posts: 694 Location: Puerto Vallarta
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Posted: Tue Apr 08, 2008 12:57 am Post subject: |
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Ataristyle wrote: |
but when it comes to a BUG motor or a BUS motor...Whats the difference...they should be the same jetting for either. |
I was looking at MOFOCO's advertisement for a 34 Pict 3 carburetor, and it doesn't say what brand it is.
I doubt seriously that it's an original Solex, so your carb could be made by either Pierburg, Brosol, Bocar, or some other company we have never even heard of.
This is not outside the realm of possibilities, since, IIRC, MOFOCO manufacturers their own head castings.
Now before somebody from MOFOCO pops in here and protests, I am not suggesting that there's anything wrong with MOFOCO's 34 Pict 3. I have no knowledge of, or experience with, their 34 Pict 3.
And that is exactly why I am suggesting that you contact them and get more information.
To borrow from that old phrase: assuming that all 34 Pict 3's, from all the various companies making them, are going to be made to some sort of exacting standard ... makes an "ass" of "u" and "me".
Oh yeah, here is a spec chart for original VW Solex carbs, so you can see that even with the originals, there was some variation.
_________________ 68 Beetle
And keeping my eye out for a Kombi or a Microbus!  |
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Ataristyle Samba Member
Joined: February 11, 2008 Posts: 135 Location: McHenry, IL
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Posted: Tue Apr 08, 2008 8:42 am Post subject: |
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Talked to MOFOCO and the Main jet is 130, Pilot Jet 60 & Air is 75. The bigger the Air corrector the more air is introduced into the carb then, correct? |
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PierreDeKat Samba Member

Joined: May 06, 2005 Posts: 694 Location: Puerto Vallarta
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Posted: Tue Apr 08, 2008 10:40 am Post subject: |
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Ataristyle wrote: |
Talked to MOFOCO and the Main jet is 130, Pilot Jet 60 & Air is 75. The bigger the Air corrector the more air is introduced into the carb then, correct? |
Something like that. The way I understand it, there's kindof a juggling thing going on between the main jet and the air correction jet.
And 130 on the main jet sounds like a pretty good starting point. You could run that for a few days and then check your tailpipes to see how sooty they are and your sparkplugs to see how black they get and work from there. _________________ 68 Beetle
And keeping my eye out for a Kombi or a Microbus!  |
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Russ Wolfe Samba Member

Joined: October 08, 2004 Posts: 25187 Location: Central Iowa
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Posted: Tue Apr 08, 2008 11:35 am Post subject: |
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Bus, Thing, and Ghia were jetted different, due to the style of air cleaner for one thing. Also, buses need to have larger jets due to the faact that the engine is working harder.
And BTW, that intake manifold on your bus is for a Type one, not a Type 2. Type 2 intake manifolds were taller on dual ports. Note how the hose from the air cleaner is going down hill to the carb.
I can look in the factory shop manual ans it should show what jets are needed for a 1600cc DP Type II. _________________ Society is like stew. If you don't keep it stirred up, you end up with a lot of scum on the top!--Edward Abbey
Gary: OK. Ima poop. |
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Russ Wolfe Samba Member

Joined: October 08, 2004 Posts: 25187 Location: Central Iowa
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Posted: Tue Apr 08, 2008 12:32 pm Post subject: |
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Russ Wolfe wrote: |
Bus, Thing, and Ghia were jetted different, due to the style of air cleaner for one thing. Also, buses need to have larger jets due to the faact that the engine is working harder.
And BTW, that intake manifold on your bus is for a Type one, not a Type 2. Type 2 intake manifolds were taller on dual ports. Note how the hose from the air cleaner is going down hill to the carb.
I can look in the factory shop manual ans it should show what jets are needed for a 1600cc DP Type II. |
I knew I had it.
_________________ Society is like stew. If you don't keep it stirred up, you end up with a lot of scum on the top!--Edward Abbey
Gary: OK. Ima poop. |
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PierreDeKat Samba Member

Joined: May 06, 2005 Posts: 694 Location: Puerto Vallarta
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Posted: Wed Apr 09, 2008 12:17 am Post subject: |
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It took me awhile to wrap my mind around it, but now it makes sense to me about the different air cleaner requiring different jets.
I think that the longer, more convoluted air cleaner setup creates a slightly stronger vacuum above the throttle plate. And that slightly stronger vacuum calls for a slightly smaller main jet to keep the fuel/air mix correct.
But yeah, I think you should shoot for Russ's Type II specs, since those are VW-approved and factor in the Type II's air filter. _________________ 68 Beetle
And keeping my eye out for a Kombi or a Microbus!  |
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Ataristyle Samba Member
Joined: February 11, 2008 Posts: 135 Location: McHenry, IL
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Posted: Wed Apr 09, 2008 4:53 am Post subject: |
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Ok, thank you much. Makes sense what you say. I'll try dialing in what I have, but more than likely will order the correct jetting setup. Thanks everyone for your help! |
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volksgroove Samba Member

Joined: October 19, 2010 Posts: 239 Location: Apopka, FL
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Posted: Thu Sep 26, 2013 7:31 am Post subject: |
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I'm running a new 1641 with Engle 110 cam, 009 with Ignitor, and German Solex 34 pict 3. I swapped the 127 main jet for a 135 and it helped tremendously. Still doesn't idle real well when cold, but is super happy when warm. Choke seems to be working, but I'm going to replace anyways. Prior to swapping the jets, she was misfiring up through the carb consistently during acceleration. After swapping jets, she did it one time on my way home... but overall, she ran much better.
Just looking for opinions from you guys as to what combo to run in my 67 double cab with a bug AE case 1641. We live in Florida, so it's hot and humid here most of the year... Bosch coil, stock heads, NGK plugs at .028", valves at .006", and full advance at 28-30 degrees. Stock German bug exhaust, and cone shaped air filter on beetle cleaner manifold. _________________ 1969 Riviera "Ethel"
1965 beetle father/son build
1988 Scirocco 16v father/son build |
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badufay Samba Member

Joined: December 13, 2010 Posts: 376 Location: Olympia, WA
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Posted: Thu Sep 26, 2013 9:55 am Post subject: |
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Don't forget manifold preheat....You can jet all day, but if you're not atomizing fuel properly you're going to be running rich as heck despite it feeling "good"
Ben _________________ Current: 2023 ID.4 Pro S, 2020 Golf TSi 1.4L, 2017 GTI S, 6 spd man, 76 Bus, 2.0L- 3 spd auto
Previous: 2015 Golf S TDI, 6 spd man; 2015 Jetta SE TDI, 6 spd man; 12 Jetta 2.5L, 04 Jetta 2.0L, 02 Golf 2.0L, 98 Jetta 2.0L, 98 Golf 2.0L, 98 Cabrio 2.0L, 95 Golf 2.0L, 87 golf GTI 16 valve 1.8L, 86 Cabriolet 1.6L, 80 Audi 4000 1.6L, 76 Audi Fox 1.6L, 76 VW Beetle 1.6L, 74 Audi Fox 1.5L, 69 VW Beetle 1.5L |
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