0384779 JOHNSON ARMATURE ASSY.

Troubleshooting
Troubleshooting can be difficult. On the following pages there is a list of possible problems. To make a repair to a problem, make reference to the cause and correction.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 cannot give all possible problems and corrections. The service personnel must find the problem and its source, then make the necessary repairs.Troubleshooting Problem List
1. Engine Will Not Turn When Start Switch Is On.2. Engine Will Not Start/Engine Starts, But Shuts Down.3. Misfiring Or Running Rough.4. Stall At Low RPM.5. Sudden Changes In Engine Speed (RPM).6. Not Enough Power.7. Too Much Vibration.8. Loud Combustion Noise.9. Loud Noise (Clicking) From Valve Compartment.10. Oil In Cooling System.11. Mechanical Noise (Knock) In Engine.12. Gas Consumption 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. Engine Has Low Oil Pressure.22. Engine Uses Too Much Lubrication Oil.23. Engine Coolant Temperature Is Too High.24. Electric Starter Motor Does Not Turn.25. Alternator Gives No Charge.26. Alternator Charge Rate Is Low Or Not Regular.27. Alternator Charge Too High.28. Alternator Has Noise.29. Short Spark Plug Life.30. Detonation.31. Gas Supply Line Shutoff Valve Failure.32. Air Starting Motor Turns Slowly Or Has A Loss Of Power.33. Air Starting Motor Pinion Does Not Engage With The Flywheel.34. Air Starting Motor Runs, Pinion Engages But Does Not Turn Flywheel.35. Air Starting Motor Pinion Does Not Engage Correctly With The Flywheel.36. Solid State Magneto (Altronic).37. Electric Protective Systems. See:Form No. SENR4616, Electric Protective System Energize To Run (SI-ETR)Form No. SENR4617, Troubleshooting Guide Electric Protective System Energize To Run (SI-ETR)Form No. SENR4618, Control Panel (Status-Timing) For 3500 Spark Ignited Engines Problem 1: Engine Crankshaft Will Not Turn When Start Switch Is On Probable Cause:1. Problem With Air Starter Motor Make reference to Problem 32.2. Problem With Electric Starter Motor Make reference to Problem 24.3. Oil Pressure Switch For Prelubrication Pump Has A Defect Make a replacement of defective switch.4. Prelubrication Oil Pump Has A Defect Repair or replace pump components as needed.5. Status Control Has Detected A Fault Or Has A Defect Refer to the Troubleshooting Section of Form No. SENR4618, Control Panel (Status-Timing) For 3500 Spark Ignited Engines.6. Timing Control Has Detected A Fault Refer to 3500 Spark Ignited Electronic Troubleshooting, Form No. SENR4612.7. Inside Problem Prevents Engine Crankshaft From Turning: If the crankshaft cannot be turned after disconnecting the driven equipment, remove the spark plugs and check for fluid in the cylinders. If fluid in the cylinders is not the problem, the engine must be disassembled to check for other inside problems. Some of these inside problems are bearing seizure, piston seizure, wrong pistons installed in the engine, and valves making contact with pistons. Problem 2: Engine Will Not Start Or Engine Starts, But Shuts Down Probable Cause:1. No Gas To Engine Check gas supply and pressure regulator. Reset shutoff valve in the supply line. Check carburetor throttle, and linkage between carburetor and governor.2. Wrong Ignition Timing Set magneto timing (see Magneto Timing).3. Timing Control Has A Defect Or Detected A Fault Refer to 3500 Spark Ignited Electronic Troubleshooting, Form No. SENR4612.4. Ignition System Failure Check the ignition transformers for loose connection, moisture, short or open circuits. Check the primary and secondary wiring. Check the spark plugs for correct type. Check the magneto. Repair or replace any component that shows signs of failure. Make reference to Problem 36.5. Gas Line Pressure Regulator Not Working Clean balance line. Check inlet and outlet regulator pressures. Disassemble and inspect.6. Carburetor Not Working Check all carburetor adjustments. Be sure that throttle plate is open and that governor permits it to open fully. Inspect the fuel-air diaphragm for leaks, dirt or wet fuel. Check the governor high idle and carburetor stop screw for low idle adjustments.7. Slow Cranking Speed Cranking speed must be at least 150 rpm. Check condition of starting system. Make reference to Problem 24.8. Electrical Shutoff System Failure Make repairs or replacements as necessary.9. Status Control Has Detected A Fault Or Has A Defect. Refer to the Troubleshooting Section of Form No. SENR4618, Control Panel (Status-Timing) For 3500 Spark Ignited Engines. Problem 3: Misfiring Or Running Rough Probable Cause:1. Ignition System Failure a. Check the ignition transformers for loose connection, moisture, short or open circuits. Check the primary and secondary wiring. Check the spark plugs for correct type. Check the magneto. Repair or replace any component that shows signs of failure. See Problem 36.b. Replace the Altronic Interface Module.c. If the problem persists, replace the Timing Control Module.2. Low Gas Pressure Check for leaks in gas supply. Check the line pressure regulator, shutoff valve and solenoid. If two or more engines are used, be sure the common supply line is large enough. Regulator pressure should not change over the normal load range. Inspect the regulator diaphragm for leaks and valve for correct seat contact. Check gas pressure before and after the line pressure regulator. Check for restriction in balance line from carburetor to regulator.3. Wrong Air/Fuel Ratio Adjust for proper free oxygen in exhaust or correct differential/pressure for fuel used.a. Make sure all connectors are tight, check for any signs of damage, or moisture in the connectors or the wiring harness.4. Wrong Valve Clearance Make adjustment according to subject, Valve Clearance.5. Bent or Broken Push Rod Replacement of push rod is necessary. Problem 4: Stalls At Low RPM Probable Cause:1. Idle RPM Too Low Increase low idle rpm.2. Too Much Load Check for attachment excessive loading. Reduce load and/or adjust throttle stop. If necessary,