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Fargo Trucks Carburetors : FARGO TRUCKS   GOVERNOR ASSEMBLY

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CARTER CARBURETOR CORPORATION, ST. LOUIS, MO., U. S. A. Page 3
GOVERNOR SERVICE INSTRUCTIONS
If governor has been tampered with, or should the adjusting screw be turned out of the primary spring due to faulty adjustment, recalibration will be necessary to insure proper operation. This will require removal of the carbureter from the engine. If recalibration is necessary, proceed as follows:
1. Determine the governor unit number (stamped on the cover plate and also on housing on later production) and refer to the chart in conjunction with Figure 2 for calibration specifications.
2. Remove lead seal plugs from the two depressed screw openings in the governor cover plate by prying out with a small screw driver. Remove all retaining screws and cover. Never attempt to remove governing lever assembly from end of throttle valve shaft.
3. Remove shaft housing and lever assembly located at end of throttle shaft opposite governor assembly. Before removal be sure to note and mark position of long throttle stop screw for correct reassembly. Never immerse this part in cleaning solvent as this may cause swelling of throttle lever shaft assembly seal.
4. Carbon or gum deposits in the throttle shaft bearing races may eventually cause friction and result in sluggish and inaccurate governor performance. Therefore, it is advisable, before proceeding with recalibration of governor, to squirt some non-corrosive solvent in the narrow space between the throttle shaft and shaft openings in the throttle bore and clean with compressed air. Do not use any solvent which might leave a gummy film. Never apply lubricating oil to the throttle shaft bearings.
5. Check fit of throttle valve in throttle bore as follows:

Hold governor valve open and with long nose pliers disconnect loop of primary spring from the governing lever link. This will allow the throttle valve to close with very little pressure from the secondary spring and makes checking of the throttle valve fit much easier. The throttle valve must not touch the bore of the carbureter flange when in any position except when completely closed. Check the centering of the valve by holding the flange up to a light, closing the valve tightly and looking through the bore. The valve should touch the bore at the idle port and also the point opposite to it. The sides of the valve near the throttle shaft should not touch the bore and approximately the same clearance should be visible on both sides: If throttle valve is not properly aligned, loosen the two attaching screws, then with the valve in closed position rotate and shift valve with the fingers to obain proper alignment. Tighten the two screws. Connect primary spring to governing lever link. Do not tap throttle valve or throttle shaft when refitting valve.
6. Remove secondary adjusting screw plug and gasket assembly and check "A" dimension of secondary adjusting screw and spring assembly. Open throttle to make sure that the secondary spring is not in contact with governing lever. Turn secondary screw clockwise to decrease dimension, and counter-clockwise to increase dimension.

Secondary spring assembly may be removed for replacement by removing retainer while pressing lightly on head of secondary adjusting screw, then backing out screw.

Upon reassembly, be sure that retainer is installed in proper slot and not against thread (see Figure 2), and that secondary spring compresses without buckling as throttle valve is closed. If spring buckles, remove secondary spring assembly and revolve entire spring assembly 1/6 turn and reinstall. If necessary, repeat until buckling condition no longer exists. Never remove secondary spring from its holder since this will damage spring.
7. Check "C" dimension (throttle valve closed). This controls the primary spring tension. (First make sure that the adjusting nut is pressed all the way into casting by tapping with tool T109-185.)

Correct "C" dimension if necessary by turning the primary adjusting screw, clockwise to increase dimension, counter-clockwise to decrease dimension.
8. Check "B" specification. This is the number of active coils. In order that the number of active coils may easily be counted, hold the throttle valve closed to separate the coils. In counting the number of active coils start at the first complete coil from the loop end as shown in Figure 3. The active coils end at the entering edge of the primary adjustment screw thread as shown in Figure 4.
If the number of active coils is within one coil of "B" specification, insert and drive fiber adjusting nut seal into governor housing (Figure 2) against adjusting nut. (A short piece of 1/4 inch pipe may be used for that purpose.) If fiber seal is already in place, do not insert another.
If the number of active coils is not within one coil of "B" specification, indications are that the spring has been tampered with and recalibration with the adjusting nut is necessary.
9. Before proceeding with the nut adjustment, check to see if the governor has the fiber adjusting nut seal. If it has, remove as follows:
Hold throttle valve open, unhook the primary spring from the link, and using a narrow screw driver, turn the primary adjusting screw clockwise until it is out of adjusting nut. Place fiber drift inside governor housing against adjusting nut and drive out nut and seal. The same method should be followed for removing primary adjusting screws and adjusting nuts for replacement if damaged whether or not governor has a fiber seal.
ENTERING EDGE OF PRIMARY FIRST COMPLETE COIL ADJUSTING SCREW
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FIGURE 4 FIGURE 3