Ford Model SNNN-6006 Engine Engine

• Voltage drops under heavy load
  Cause: Engine lacks power. Poor compression. Faulty carburetion. Restricted air cleaner. Excessive choking. Carbon in cylinders. Restricted exhaust line.
  Fix: See remedies for engine missing under heavy load. Tighten cylinder head and spark plugs. If still not corrected, grind the valves. Replace piston rings, if necessary. Check the fuel system. Clean, adjust or replace parts necessary. Clean and refill. See that choke opens properly. Remove carbon. Clean or increase the size.
• Excessive oil consumption, light blue smoky exhaust
  Cause: Poor compression, usually due to leaking valves.
  Fix: Tighten cylinder head and plugs. If still not corrected, grind or replace valves. Oil leaks from engine or connections. This does not cause smoky exhaust. Tighten screws and connections. Oil too light or diluted. Drain, refill with correct oil. Too large bearing clearance. Replace. Oil pressure too high. Refer to symptoms of high oil pressure for remedies. Engine misfires. Refer to symptoms of engine misfires. Faulty ignition. Clean, adjust, or replace breaker points, plugs, condenser, coil, etc., or retime ignition. Unit operated at light or no load for long periods. No remedy needed. Too much oil. Drain excess oil.
• Engine runs but current does not build up
  Cause: Poor brush contact. Open circuit, Short circuit, or ground in generator.
  Fix: See that brushes seat well, are free in holders, are not worn too short, and have good spring tension. See GENERATOR, replace part necessary.
• Engine overheating
  Cause: Overloaded.
  Fix: Reduce load.
• Engine misfires at light load
  Cause: Carburetor idle adjustment set wrong or clogged. Spark plug gaps too narrow. Intake air leak. Faulty ignition. Uneven compression.
  Fix: Adjust to correct gap. Tighten or replace gaskets. Clean, adjust, or replace breaker points, plugs, condenser, coils, etc., or retime ignition. Tighten cylinder head and spark plugs. If still not corrected, grind valves. Replace piston rings, if necessary. Worn intake valve stems. Replace valves.
• Engine misfires at heavy load
  Cause: Spark plugs defective. Faulty ignition.
  Fix: Replace. Clean, adjust, or replace breaker points, plugs, condenser, coil, etc., or retime ignition.
• Engine backfires at carburetor
  Cause: Lean fuel mixture. Clogged fuel screen. Intake air leak.
  Fix: Clean carburetor. Clean screen. Replace flange gaskets, tighten carburet. Poor fuel. Refill with good, fresh fuel. Spark too late. Retime ignition. Spark plug wires crossed. Install wires correctly. Intake valves leaking. Grind or replace.
• Current steady but engine not misfiring
  Cause: Speed too low. Poor commutation or brush contact. Loose connections. Fluctuating load.
  Fix: Adjust governor to correct speed. Tighten connections. Correct any abnormal load condition causing trouble.
• Black, smoky exhaust, excessive fuel consumption, fouling of spark plugs with black soot. Possible lack of power under heavy load
  Cause: Fuel mixture too rich.
  Fix: Adjust choke. Install needed carburetor parts, adjust float level. Choke not open. See that choke opens properly. Dirty air cleaner. Clean, refill to proper level.
• Voltage low at far end of line but normal near power unit
  Cause: Too small line wire for load
  Fix: Install larger or extra wires or reduce and distance
• Tappingsound
  Cause: Taplet clearance too great
  Fix: Adjust or replace tappets
• Sharp metallic thud, especially when cold engine first started
  Cause: Low oil supply
  Fix: Add oil
• Pinging sound when engine is rapidly accelerated or heavily loaded
  Cause: Carbon in cylinders
  Fix: Remove carbon
• Noisy brushes
  Cause: High mica between bars of commutator
  Fix: Undercut mica.
• Motors run too slowly and overheat at far end of line but not near power unit
  Cause: Too small line wire for load
  Fix: Install larger or extra wires, or reduce and distance

Compiled from service & troubleshooting documentation across every generator set that uses the Ford Model SNNN-6006.

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.