Dell’Orto carburetors

This information is intended to supplement the information available in the Moto Guzzi spare parts catalogs and workshop manuals. Dell’Orto is commonly spelled Dellorto or Dell Orto or Delorto or Del Orto or Del'Orto.

Dell’Orto - A Guide 1.1 to the choice, setting and use of tapered-needle motorcycle carburettors

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Thanks to Ken Wisdom for sending me this document.

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Dell’Orto carburetor manual

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This information was gleaned from Dell’Orto.

This manual applies to many carburetors and covers the following:

• Carburetor: Basic principles
• The idle circuit and the progression
• The main circuit
• The carburetor: The additional systems
• The vacuum carburetor
• The venturi and the airflow control

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Dell’Orto - Features and tunings of some parts of the new range of carburettors

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Thanks to Ken Wisdom for sending me this document.

To view PDF files, you will need to download and install the free Adobe Acrobat Reader version 5.0 or higher.

NOTE: If you have trouble viewing PDF files inside your browser, try saving them to your computer (right-click the link, then choose the save option). Then, open each file directly in Adobe Acrobat Reader.

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Setting the float height

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This information was gleaned from eurocarb.

Whenever the float or float-arm position does not correspond to the proper specified level setting or is not parallel to the float chamber face, bend the float arms carefully to set the correct position.

Table: Dell’Orto carburetor float height values

Carburettor	Float height, millimeters
PHBG	16 +/- 0.5
PHBL	24 +/- 0.5
PHBH	24 +/- 0.5
PHBE	18 +/- 0.5
PHF	18 +/- 0.5
PHM	18 +/- 0.5
VHB/Z/T	24 +/- 0.5
PHSB*	11 +/- 0.5
VHSA*	11 +/- 0.5
VHSB*	11 +/- 0.5
* PHSB/VHSA/VHSB one piece float assembly.

• For connected floats, hold the carburettor body in the position shown in fig. 13 and check that the float is at the correct distance from the carburettor body face as specified in the table.
• For the floats with independent parts, hold the carburettor upside down (fig. 14) and check that the float arm is parallel to the carburettor face.

What is the difference between connected floats with floats with independent parts?

Thanks to Charlie Mullendore of Antietam Classic Cycyle who posted this information on the Yahoo! Loopframe_Guzzi news group.

My take on it is:

• Independent floats slide up and down on a steel pins and aren't connected in any way. There are two floats and one common central "V" or "U" shaped metal piece that act upon that controls the needle.
• Connected is two floats attached to a common central "V" or "U" shaped metal piece. This is the type VHBs use.

Figure 13: setting the float on carburetors with connected floats

Figure 14: setting the float on carburetors with independent parts

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