External Engine Inspection; Cleaning The Engine - Kohler Courage SV470 Service Manual

Section 3
Troubleshooting
Engine Overheats
1. Air intake/grass screen, cooling fins, or cooling
shrouds clogged.
2. Excessive engine load.
3. Low crankcase oil level.
4. High crankcase oil level.
5. Faulty carburetor.
6. Lean fuel mixture.
Engine Knocks
1. Excessive engine load.
2. Low crankcase oil level.
3. Old or improper fuel.
4. Internal wear or damage.
5. Quality of fuel.
6. Incorrect grade of oil.
Engine Loses Power
1. Low crankcase oil level.
2. High crankcase oil level.
3. Dirty air cleaner element.
4. Dirt or water in the fuel system.
5. Excessive engine load.
6. Engine overheated.
7. Faulty spark plug.
8. Low compression.
9. Exhaust restriction.
10. Low battery.
11. Incorrect governor setting.
Engine Uses Excessive Amount of Oil
1. Incorrect oil viscosity/type.
2. Clogged, broken, or inoperative breather.
3. Worn or broken piston rings.
4. Worn cylinder bore.
5. Worn valve stems/valve guides.
6. Crankcase overfilled.
7. Blown head gasket/overheated.
Oil Leaks from Oil Seals, Gaskets
1. Clogged, broken, or inoperative breather.
2. Worn or broken piston rings.
3. Piston blowby, or leaky valves.
4. Restricted exhaust.

External Engine Inspection

Before cleaning or disassembling the engine, make a
thorough inspection of its external appearance and
condition. This inspection can give clues to what
might be found inside the engine (and the cause)
when it is disassembled.
3.2
• Check for buildup of dirt and debris on the
crankcase, cooling fins, grass screen and other
external surfaces. Dirt or debris on these areas
can cause overheating.
• Check for obvious oil leaks and damaged
components. Excessive oil leakage can indicate
a clogged or inoperative breather, worn or
damaged seals or gaskets, or loose fasteners.
• Check the air cleaner cover and base for damage
or indications of improper fit and seal.
• Check the air cleaner element. Look for holes,
tears, cracked or damaged sealing surfaces,
or other damage that could allow unfiltered
air into the engine. Also note if the element is
dirty or clogged. These could indicate improper
maintenance.
• Check the carburetor throat for dirt. Dirt in the
throat is further indication that the air cleaner
was not functioning properly.
• Check if the oil level is within the operating range
on the dipstick. If it is above, sniff for gasoline
odor.
• Check the condition of the oil. Drain the oil into
a container; it should flow freely. Check for metal
chips and other foreign particles.
Sludge is a natural by-product of combustion; a small
accumulation is normal. Excessive sludge formation
could indicate the wrong type or weight of oil was
used, the oil was not changed at the recommended
intervals, an over-rich fuel mixture, or weak ignition,
to name a few possible causes.
NOTE: It is good practice to drain oil at a location
away from the workbench. Be sure to allow
ample time for complete drainage.

Cleaning the Engine

After inspecting the external condition of the engine,
clean the engine thoroughly before disassembling
it. Also clean individual components as the engine
is disassembled. Only clean parts can be accurately
inspected and gauged for wear or damage. There
are many commercially available cleaners that
will quickly remove grease, oil, and grime from
engine parts. When such a cleaner is used, follow
the manufacturer's instructions and safety precautions
carefully.