18787 3 Mercury CYLINDER HEAD

The following procedures are used in order to adjust Type IV and some Type III governors after the governors have been assembled. There are certain governor adjustments that must be performed during governor assembly. Refer to the Disassembly and Assembly, "Governor (Type) - Assemble" section in this manual.
Install the governor on the 1U-7326 Governor Calibration Bench. Refer to the Testing and Adjusting, "Installation of Governor on 1U-7326 Governor Calibration Bench " section in this manual.
Verify the position of the throttle lever. Refer to the Testing and Adjusting, "Throttle Lever Orientation (Types IV, V, VI, VII, And Some III) - Check" section of this manual for more information.
If the throttle lever was positioned properly, proceed with Step 4. If the throttle lever was not positioned properly, refer to the Testing and Adjusting, "Throttle Lever (Types IV, V, VI, VII, And Some III) - Remove" and Testing and Adjusting, "Throttle Lever (Types IV, V, VI, VII, And Some III) - Install" sections in this manual for more information.Note: If the governor is equipped with a fuel ratio control, a regulated air supply of 140 to 210 kPa (20 to 30 psi) must be connected to the fuel ratio control during the adjusting procedure (except as noted during the fuel ratio control setting steps).
Illustration 1 g00780280
(A) Access hole for the load stop adjustment screw and the fuel ratio adjustment screw
Remove the plug from access hole (A). To remove the plug, use a hammer and a punch to pierce the center of the plug. Then use a suitable prybar to remove the plug from the access hole.
Illustration 2 g00660334
Illustration 3 g00660348
(1) Spring (2) Throttle stop adjustment screw (3) Low idle adjustment screw (4) Load stop adjustment screw
Make sure that low idle adjustment screw (3) and throttle stop adjustment screw (2) are backed out so the end of the screw is not extending past the housing face.Connect spring (1) to the test bench and to the throttle in order to hold the throttle against the throttle stop.
Use a 1U-6672 Rack Adjusting Wrench to loosen load stop adjustment screw (4). Loosen the load stop adjustment screw until the end of the screw is even with the face of the governor housing.
Illustration 4 g00660344
(5) Tachometer (6) Speed control knob
Connect the test bench to an electrical outlet. Turn on tachometer (5) .
Turn the switch for the test bench to the ON position.
Do not turn the speed control knob unless the test bench is running. Damage to the variable speed drive may result. Except in the event of an emergency, the speed control knob should always be returned to the slowest rpm setting before the calibration bench is turned off.
Turn speed control knob (6) in the counterclockwise (CCW) direction to the slowest speed. Check all fluid connections for leaks. If leaks are found, perform any necessary repairs.Note: Always approach a specified rpm setting from a minimum of 100 rpm above the rpm that is required. This will ensure that the test readings are consistent for the entire test procedure.Note: All specifications for the governor adjustment procedure are in the Technical Marketing Information (TMI). If no values are listed in the specifications for a particular functional test, proceed to the next step in the test.Note: If any of the adjustments for the function checks cannot be performed during the governor setting procedure, stop the procedure and inspect the governor for possible problems.Note: The tolerances that are found in the TMI, refer to the Specifications, "Governor Performance Data" section in this manual, are applicable to all of the governor adjustments. The Expanded Tolerance Band that is referred to in the governor checking procedure is applicable to rechecking a governor that has been previously adjusted.
Illustration 5 g00660334
Illustration 6 g00660348
(1) Spring (2) Throttle stop adjustment screw (3) Low idle adjustment screw (4) Load stop adjustment screw
Adjust the speed on the calibration bench to the "LOAD STOP ADJ" rpm that is specified in the TMI. Adjust load stop adjustment screw (4) to the output dimension that is specified in the TMI.
Tighten the locknut for load stop adjustment screw (4) and check the output dimension again.
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