20709580 Volvo.Penta Valve cover

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 correction 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 cannot give all possible problems and corrections. The serviceman must find the problem and its source, then make the necessary repairs.1. Engine 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 (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 Lash.15. Valve Rotocoil Or Spring Lock Is Free.16. Oil At The Exhaust.17. Little Or No Valve Lash.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 Is Too Hot.24. 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. Pre-Ignition.31. Detonation.32. Gas Supply Line Shutoff Valve Failure.33. Failure Of Overspeed Contactor Switch To Shutoff Engine.34. Overspeed Contactor Stops Engine At Low Speed.35. Solid State Magneto (Altronic).36. Contactor Switch (Water Temperature) Fails to Signal Shutoff.37. Contactor Switch (Water Temperature) Signals Shutoff at Low Temperature.38. Oil Pressure Contactor Fails to Signal Shutoff.39. Overspeed Contactor Switch Fails to Signal Shutoff.40. Overspeed Contactor Switch Signals Shutoff at Low Speed. Problem 1: Engine Crankshaft Will Not Turn When Start Switch Is On Probable Cause:1. Battery Has Low Output: Make reference to Problem 24.2. Wiring Or Switches Have Defect: Make reference to Problem 24.3. Starter Motor Solenoid Has A Defect: Make reference to Problem 24.4. Starter Motor Has A Defect: Make reference to Problem 24.5. 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 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: Time magneto to engine.3. Timing Failure: Check the ignition transformers for loose connection, moisture, short or open circuits. Check the low and high tension wiring. Check the spark plugs for correct type and spark plug adapters. Check the magneto. Repair or replace any component that shows signs of failure.4. Carburetor Not Working: Check all carburetor adjustments. Be sure that throttle plate is open and that governor permits it to open fully. Check the BTU content of the fuel based on lower heat value (LHV). If it is too low, a higher fuel pressure (correct spring force in the regulator), or a special carburetor may be needed. Inspect the fuel-air diaphragm for leaks, dirt or wet fuel. Check the governor high idle and carburetor stop screw for low idle adjustments.5. Slow Cranking Speed: Cranking speed must be at least 150 rpm. Check condition of starting system. See Problem 24.6. Engine protection system is grounding magneto output. Engine stop-bypass switch must be activated during engine startup until oil pressure is achieved. Problem 3: Misfiring Or Running Rough Probable Cause:1. Ignition Failure: Make reference to Problem 2.2. 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. Set valve lash. Problem 4: Stalls At Low RPM Probable Cause:1. Idle RPM Too Low: Make adjustment to the throttle stop screw at the carburetor.2. Too Much Load: Check for attachment excessive loading. Reduce load and/or adjust throttle stop. If necessary, disconnect attachments and test engine. Problem 5: Sudden Changes In Engine Speed (RPM) Probable Cause:1. Governor Failure: Look for damaged or broken springs, linkage or other components. Check governor-to-carburetor linkage or other components. Check for correct spring. Check governor oil pump and bypass valve.2. Wrong Adjustment Or Leaky Valve: Make adjustment to the valves.3. Turbocharger Differential Pressure Control Valve Failure: Inspect the valve. Check valve diaphragm and boost air hose for leakage. Check breather element for plugging.4. Governor Or Linkage Adjustment Incorrect: Check to see if linkage between governor and carburetor operates smoothly and has no free play. Make adjustment to the governor and linkage as necessary. Problem 6: Not Enough Power Probable Cause:1. Low Gas Pressure Or Gas Line Pressure Regulator Failure: Clean balance line. Check inlet and outlet regulator pressures.2. Carburetor Adjustment Or Carburetor Not Working: Make reference to Problem 2.3. Leaks In Air Induction System: Check air cleaner for restriction. Check inlet manifold pressure on turbocharger engines.4. Governor Control Linkage And/Or Throttle Valve Balance (Synchronized): Adjust linkage and make adjustment to throttle valve balance (synchronize).5. Too Much Valve Lash: Make adjustments according to the subject Valve Lash.6. Ignition Wiring Failure: Check for damage to wiring, arcing, or bare wire.Check rubber boot over spark