87379A14 Mercury WIRE ASSEMBLY, (2.750 Inches)

Troubleshooting
Troubleshooting can be difficult. The TROUBLESHOOTING INDEX gives a list of possible problems. To make a repair to a problem, make reference to the cause and corrections on the pages that follow.This list of problems, causes, and corrections, will only give an indication of where a possible problem can be, and what repairs are needed. Normally, more or other repair work is needed beyond the recommendations in the list. Remember that a problem is not normally caused only by one part, but by the relation of one part with other parts. This list is only a guide and can not give all possible problems and corrections. The serviceman must find the problem and its source, then make the necessary repairs.Troubleshooting Index
1. Engine Crankshaft Will Not Turn When Start Switch is On.2. Engine Will Not Start.3. Misfiring or Running Rough.4. Stall at Low rpm.5. Sudden Changes In Engine Speed.6. Not Enough Power.7. Too Much Vibration.8. Loud Combustion Noise (Knock).9. Loud Noise (Clicking) From Valve Compartment.10. Oil In Cooling System.11. Mechanical Noise (Knock) In Engine.12. Gas Comsumption Too High.13. Loud Noise From Valves or Valve Drive Components.14. Little Movement of Rocker Arm and Too Much Valve Clearance.15. Valve Rotocoil or Spring Lock is Free.16. Oil at the Exhaust.17. Little or No Valve Clearance.18. Engine Has Early Wear.19. Coolant in Lubrication Oil.20. Exhaust Temperature is Too High.21. Too Much White or Blue Smoke.22. Engine Has Low Oil Pressure.23. Engine Uses Too Much Lubrication Oil.24. Engine Coolant Is Too Hot.25. Starter Motor Does Not Turn.26. Alternator Gives No Charge.27. Alternator Charge Rate Is Low or Not Regular.28. Alternator Charge Too High.29. Alternator Has Noise.30. Solenoid Does Not Stop Engine.31. Short Spark Plug Life.32. Preignition.33. Detonation.34. Gas Supply Line Shutoff Valve Failure.35. Instrument Panel Gauge Switches Do Not Stop Engine.36. Instrument Panel Gauge Switches Prevent Engine Start.37. Failure of Overspeed Contactor Switch to Shutoff Engine.38. Overspeed Contactor Stops Engine at Low Speed.39. Air Starting Motor Turns Slowly.40. Troubleshooting Solid State Magneto. (Fairbanks Morse) 40A. Missing on One or More Cylinders.40B. Engine Dead and Has No Spark.41. Troubleshooting Solid State Magneto. (Altronic) 41A. Missing on One or More Cylinders.41B. Engine Dead and Has No Spark.Engine Crankshaft Will Not Turn When Start Switch Is On. Engine Will Not Start Misfiring Or Running Rough Stall At Low RPM Sudden Changes In Engine Speed Not Enough Power Too Much Vibration Loud Combustion Noise (Knock) Loud Noise (Clicking) From Valve Compartment Oil In Cooling System Mechanical Noise (Knock) In Engine Gas Consumption Too High Loud Noise From Valves Or Valve Drive Components Little Movement Of Rocker Arm And Too Much Valve Clearance Valve Rotocoil Or Spring Lock Is Free Oil At The Exhaust Little Or No Valve Clearance Engine Has Early Wear Coolant In Lubrication Oil Exhaust Temperature Is Too High Too Much White Or Blue Smoke Engine Has Low Oil Pressure Engine Uses Too Much Lubrication Oil Engine Coolant Is Too Hot Starter Motor Does Not Turn Alternator Gives No Charge Alternator Charge Rate Is Low Or Not Regular Alternator Charge Too High (As Shown By Battery Needs Too Much Water) Alternator Has Noise Solenoid Does Not Stop Engine Short Spark Plug Life Preignition Detonation Gas Supply Line Shutoff Valve Failure Instrument Panel Gauge Switches Do Not Stop Engine Instrument Panel Gauge Switches Prevent Engine Start Failure Of Overspeed Contactor Switch to Shutoff Engine Overspeed Contactor Stops Engine At Low Speed Air Starting Motor Turns Slowly Troubleshooting Solid State Magneto (Fairbanks Morse)
Be sure to reconnect "H" lead to shutdown circuit after repairs are made. Failure to do so will leave the engine unprotected and damage could result.
Troubleshooting Solid State Magneto (Altronic)
Be sure to reconnect the wire to the magnetic switch and the connector to the magneto after the repairs are made.
Ignition System
To make a test of the magneto on the engine, check the condition (intensity) of the spark at the spark plug. Remember that the condition of the instrument panel components: magnetic switch, stop switch, oil pressure gauge and water temperature gauge have an effect on the output of the magneto. A defect in, or an activated overspeed shutoff contact or gas line solenoid valve can cause an indication of a defect in the magneto.A test of the magneto off the engine can be used to find a defect in the electrical components. The 2P2340 Magneto Test Bench is used to make the tests. Special Instruction Form No. GEG02059 gives the complete test procedure.Finding Top Center Compression Position For No. 1 Piston
2P8300 Engine Turning Tool Group.No. 1 piston at top center (TC) on the compression stroke is the starting point for all timing proced