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Zenith-Stromberg Troubleshooting Guide

Last post 03-29-2007, 2:19 PM by TechTipAdmin@Moss. 0 replies.
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  •  03-29-2007, 2:19 PM 5592

    Zenith-Stromberg Troubleshooting Guide

    Poor Idle Quality :
    Air leakage (check gaskets and vacuum fittings)
    Throttles not synchronised (re-balance carbs & reset linkage)
    Air valve sticking (clean & reassemble)
    Obstructed float chamber or diaphragm vent holes
    (ensure that air filter and gaskets are correctly fitted)
    Incorrect fuel level (clean or replace needle valves & reset float height)
    Metering needle wrong or incorrectly fitted (check needle number, and install to correct height)
    Diaphragm incorrectly located or damaged (holes on bottom of piston should
    be in line with and face throttle shaft - replace damaged diaphragm)
    Temperature compensator faulty (with engine & carb cold, compensator cone must be seated, but free to move off its seat)
    Vacuum leak around throttle shaft (replace seals and/or shafts)
    Hesitation or "Flat Spot":
    In addition to the above, check:
    Piston damper inoperative (ensure damper is filled to proper level with correct oil - check operation by raising piston, whereupon resistance should be felt)
    Air valve spring missing or damaged
    Ignition timing incorrect
    Throttle linkage operation incorrect (readjust and check for correct operation)
    Heavy Fuel Consumption:
    In addition to all of the above, check for fuel leakage
    Lack of Engine Braking:
    Faulty bypass valve (replace diaphragm or entire unit)
    Throttles sticking open
    Ignition retard inoperative (if separate retard unit fitted to distributor, check operation - if not, ensure that distributor returns from advanced position)
    Lack of Engine Power:
    Damaged air valve diaphragm
    Low fuel flow (check fuel pump output, needle valve & seat assemblies, and float height)

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