Description

Solex 28 VFIS, 28 PCI, 32 PICB, 40 ICB, 32 PAITA Technical Manual

If you have ever chased a fuel-spitting Solex through a set of mismatched jets, you know the value of factory documentation. I have seen techs swap main jets three times on a 28 PCI because the aftermarket “jet chart” was rounded off. That is how you burn a piston. This 48-page Solex 28 VFIS, 28 PCI, 32 PICB, 40 ICB, 32 PAITA Technical Manual is the original Arnolt Corporation publication that gives you the numbers you can trust. Not a reprint. Not a scan with missing pages. The full TOC is intact, from the float system to the automatic starter appendix. You want to select the right choke tube K? Page 20. You need the accelerator pump settings? Page 26. Every spec came off the factory floor in Warsaw, Indiana.

Selection of the Carburetor: Air Flow Direction and Venturi Sizing

Section II (page 7) walks you through choosing the right direction of air flow for your application – downdraught, side-draught, or updraught – and matching the carburetor size to your engine displacement. For a 4-cylinder sports engine or a supercharged 8-cylinder, the manual gives specific guidance on selecting the number of carburetors and the venturi diameter. Do not guess. The factory engineers already did the math on the 28 VFIS and 32 PAITA compound carb. Follow the table on page 8 and you eliminate the lean-ribbon nightmares that keep blowing engines at autocross.

The Main Jet Circuit: Choke Tube, Main Jet, and Emulsion Tube Combos

Chapter IV, Section 4 (page 20) is where most DIYers mess up. The manual breaks down the selection of the choke tube K, main jet Gg, air correction jet a, and the emulsion tube s. Five jet assemblies (No. 12, 18, 21, 22, and the new assemblies) are detailed with cross-sections on pages 22-25. If you are rebuilding a 40 ICB for a vintage British sports car, you need these profiles. Aftermarket manuals will tell you “install the correct jet” without telling you what “correct” is. This manual gives you the exact orifice diameters and air-bleed hole patterns. No shortcuts.

Operating Faults: 14 Causes and Their Corrections

Pages 35-38 list fourteen operating faults – cold starting impossible, hot starting difficult, backfiring, detonation in the exhaust, heavy consumption. Each fault has a direct cause and a specific fix. For example, “Backfiring in the carburetor” on page 38 points to a mixture too weak due to a blocked main jet or incorrect float level. The section on mixture too rich (page 38) warns against over-jetting the 28 PCI when you slap on a free-flow exhaust. I have seen that mistake wreck a fresh rebuild. The manual also covers altitude corrector (page 34) and depression-operated ignition advance (page 35) – things most tuner guides ignore entirely. If you care about driveability above 5,000 ft, this is the only source.

Audience Fit: Who Needs This Manual

Home garage enthusiasts rebuilding a vintage Solex on a 32 PICB – you need this. Professional mechanics restoring a multi-carburetor setup on a European classic – you need this. Beginners who have never cracked a carburetor open – the manual assumes you know the difference between a float and a jet, but it does not waste time teaching basic tools. It gets straight to the tuning tables on page 31: normal 4-cylinder engines, sports engines, 1-3 cylinder engines. Each table lists carburetor model, choke tube, main jet, air correction jet, idling jet, and pump jet. That is the kind of data you hang on the wall. For related factory documentation, check the Drogobych Crane KTA-16/25/28 2004 Installation Manual – Section: Общие Указания and the MODULOS DISPONIBLES PARA EL MULTIEQUIPO CJ EURO. Also see the Minsk MMVZ-3.11212 Technical Manual for other mechanical systems. For broader context on automotive diagnostics, read the Automotive Industry Overview and understanding Manual Transmission fundamentals.

Source Validity: Why Arnolt Corporation Specs Beat Aftermarket

This manual is an original Solex publication distributed by Arnolt Corporation, not a third-party compilation. The difference? Factory manuals include the “why” behind the spec – like why the 40 ICB uses a specific by-pass orifice for idling (page 19) explained with airflow diagrams. Aftermarket versions often skip the emulsion tube selection logic, leaving you to guess between mono-jet and bi-jet idling. I refuse to put a carburetor together without the factory data. If you do the same, buy the real thing.

FAQ

Does this manual cover all five listed Solex models?

Yes. The front cover lists 28 VFIS, 28 PCI, 32 PICB, 40 ICB, and 32 PAITA. Each model has dedicated tuning tables and jet specifications.

What page has the accelerator pump data?

Page 26. That section covers pump stroke adjustment and jet sizing for the 28 PCI and 32 PICB. Use it to fix that stumble on throttle tip-in.

Can I use this manual for a 32 PAITA compound carb?

Absolutely. The 32 PAITA is covered in the “New Jet Assemblies” section on page 25 and the tuning table on page 32. The compound design is explained with the starter system – both strangler and disc valve types.

Is this a photocopy or an original factory scan?

It is a factory-original technical manual in digital form – 48 pages, complete with all diagrams. The pages are clean and readable. No reprint, no guesswork.

Access the Factory Manual. Stop throwing parts at your Solex and start following the engineering that made these carbs reliable. You will save yourself the headache of a lean backfire and the cost of a melted piston. The spec is here – just open the file.