TM 10-3930-653-14&P Condition Probable cause Corrective action Low or no current Check for loose terminal or disconnection in. primary circuit. Check for burned points. Ignition Burned distributor point Repair or replace. trouble Improper point gap Adjust. Faulty condenser Replace. Leak at rotor cap and rotor Clean or replace. Faulty spark plug Clean, adjust plug gap or replace. Improper ignition timing Adjust. Faulty ignition coil Replace. Disconnection of high tension cable Replace. Loose  connection  or  disconnection  in Repair or replace. primary circuit Fuel system trouble Lack of fuel Supply. Dirty fuel strainer Replace. Dirty or clogged fuel pipe Clean. Fuel pump will not work properly Repair or replace. Carburetor choke will not work properly Check and adjust. Improper adjustment of float level Correct. Improper Idling Adjust. Dirty or clogged carburetor Disassemble and clean. Clogged breather pipe of fuel tank. Repair and clean. Low compression Incorrect spark plug tightening or damaged Tighten to normal torque or replace gasket. gasket.. Improper grade engine oil or low viscosity. Replace with proper grade oil. Incorrect valve clearance Adjust. Compression leak from valve seat Remove cylinder head and lap valves. Sticky valve stem Correct or replace valve and valve guide. Weak or defective valve springs Replace valve springs. Compression leak at cylinder head gasket Replace gasket. Sticking or worn piston ring. Replace piston rings. Worn piston ring or cylinder Overhaul engine. (Trouble shooting procedure) Pour engine oil into plug hole, and then measure cylinder compression Compression increases. Trouble in cylinder or piston ring Compression does not change. Compression leaks from valve, cylinder head or head gasket 4 - 3