12. Engines lose horsepower with increase in altitude. The percentage of power loss is governed by the
altitude at which the engine is operating.
13. Fill oil bath air cleaners to the proper level with the same grade and viscosity lubricating oil that is used in
Clean the air box and drain tubes to prevent accumulations that may be picked up by the air stream and enter
the engine's cylinders.
Inspect the blower oil seals by removing the air inlet housing and watching through the blower inlet for oil radi-
ating away from the blower rotor shaft oil seals while the engine is running. If oil is passing through the seals,
overhaul the blower.
Check for a defective blower-to-block gasket. Replace the gasket, if necessary.
14. Refer to Item 1 of this chart.
15. Check injector timing and the position of each injector rack. Perform an engine tune-up, if necessary. If
the engine is correctly tuned, the erratic operation may be caused by an injector check valve leaking, spray tip
holes enlarged or a broken spray tip. Replace faulty injectors.