850030F 1 Mercury BOTTOM YOKE

Troubleshooting Problems
The Engine Crankshaft Will Not Turn.
Probable Cause
Problem with the starting motorRefer to information on the starting motor in this section.
Fluid in the cylindersInspect the cylinders for fluid while the crankshaft is being turned.The Engine Will Not Start and the Terminal Shaft of the Governor Does Not Move.
Probable Cause
Binding of the Control linkage The engine can start when the engine is cold. When the oil is hot, the governor does not develop the oil pressure that is needed to move the linkage. Check the linkage effort and correct the problem.
Low oil pressure in the governorThe governor oil pump relief valve may be stuck in the open position or the valve may be leaking. Correct the condition by disassembly and cleaning of the governor. Refer to Caterpillar 3161 Governor, SENR3028. Check for plugged oil supply passages from the engine. The Engine Will Not Start but the Terminal Shaft of the Governor Moves.
Probable Cause
Slow cranking speedRefer to information on the starting motor in this section.
Low quality fuel or water in fuelRemove the fuel from the fuel tank. Install new fuel filters. Put a good grade of clean fuel in the fuel tank.
No fuel to fuel injectorsCheck the fuel level in the fuel tank and fill the fuel tank, if necessary. Use the priming pump in order to remove any air from the fuel system.Install new fuel filters, if necessary. Fuel lines that are blocked should be cleaned and fuel lines that are broken should be replaced. Check the fuel transfer pump for damage and/or wear.The governor linkage is not connected to the internal rack linkage. This condition can exist after a governor has been assembled incorrectly during an overhaul. Ensure that the governor linkage is correctly engaged.
Low fuel pressureAt starting rpm, the minimum fuel pressure from the fuel transfer pump must be 415 kPa (60 psi). If the fuel pressure is less than 415 kPa (60 psi), change the fuel filters. After changing the fuel filters, inspect the fuel system for air in the fuel system. If the fuel pressure is still low, check the fuel bypass valve and the fuel transfer pump for correct operation.
Wrong fuel injection timingAdjust the timing. Refer to Testing and Adjusting, "Fuel Injector Timing".
The air inlet shutoff valve is tripped.Reset the air inlet shutoff valve.The Engine Overspeeds on Start-up.
Probable Cause
Fuel control linkageInspect the fuel control linkage for one or more of the following conditions:
Incorrect assembly after overhaul
Bound fuel control linkage
Bound fuel control linkage in FUEL-ON position
Governor output lever to control housing lever out of adjustmentMake adjustment or repair.
Governor problemRefer to 3161 Governor Service Manual, SENR3028.
The governor actuator is not engaged in the drive coupling.Ensure that the governor is driven by the engine. If necessary, remove the governor and install the governor again in order to ensure that the engine is engaged correctly with the governor drive. Also, check for drive components in the governor and in the engine that are worn or damaged.Unstable Engine Speed
Probable Cause
MisfireRefer to "The Engine Misfires or the Engine Runs Rough.". Refer toTesting and Adjusting, "Fuel Systems".
Bound linkage or worn linkage with flat spots and high clearancesInspect the linkage. Repair the linkage or replace the linkage, as needed.
The linkage from the governor to the engine does not move freely.Refer to Specifications, "Governor Linkage".
Excessive play in the linkage from the governor to the engineAdjust the linkage. Repair the linkage or replace the linkage.
Rough governor driveWorn splines and/or high gear clearances can cause rough governor drive. Inspect parts and replace parts, if necessary.
Governor problemRefer to 3161 Governor Service Manual, SENR3028.
The compensation adjustments are incorrect.Adjust the needle valve and the compensation pointer.
Dirty oil in the governorDrain the oil. Clean the governor and fill the governor with the correct weight of oil.
The oil level in the governor is low.Add oil to the correct level. Check for leaks.
Air in the governor oil Drain oil. Refill with correct weight of oil.
The governor parts are worn.Disassemble the governor and inspect the following components: pilot valve, power piston, flyweight pins, pin bearings, flyweight toes, flyweight head thrust bearings and centering bearing. Operation of all parts should be smooth and free. Repair the parts or replace the parts, if necessary.
The governor oil pressure is low.Drain the governor and clean the governor. Inspect the oil pressure relief valve of the governor. If necessary, replace the valve. Inspect the check valves of the pump. Inspect the valve seats of the pump. If necessary, replace the valve. Inspect the oil pump of the governor. If necessary, repair the pump. Fill the governor with new oil of the correct weight. Purge any air from the oil passages that are in the governor.
The power piston is sticking.Check alignment of piston, power link, and power lever. Check for end play of the terminal shaft.
Seized injectorReplace the injector.
Seized piston and/or stuck piston ringsReplace piston assembly and cylinder liner.
The voltage regulator does not operate correctly.Replace the alternator voltage regulator.The Engine High Idle Speed Is Too Low.
Probable Cause
The speed setting control shaft is not against the high idle stop.Check the speed control linkage and the pneumatic controls for restrictions. If necessary, carry out repairs or replacement.
Incorrect high idle adjustmentThe governor speed setting shaft is against the high idle stop and the high idle is too low. Adjust to the correct high idle. Also, check the engine fuel setting in order to ensure that the engine fuel setting is correct.
Adjustable Speed Droop Is Incorrect.The 3161 has an internal adjustable speed droop which is set at the factory. If adjustment is necessary, refer to 3161 Governor Service Manual, SENR3028.
The speed setting solenoid adjustment of the Woodward PGEV governor is not correct.Refer to 3161 Governor Service Manual, SENR3028.The Engine High Idle Declines after Start-up.
Probable Cause
Loss of normal rpmThe loss of approximately 20 rpm can be expected as the engine warms to operating temperature.
Incorrect high idle adjustmentIf necessary, adjust the idle in order to correct high idle. Also, check the engine fuel setting in order to ensure that the engine fuel setting is correct.The Engine Cannot Be Shut Down through th