Pre-Operation Check - Hyundai PT3900-JY Instruction Manual

At high altitude, the standard carburetor air-fuel mixture will be excessively rich. Performance will
decrease, and fuel consumption will increase.
High altitude performance can be improved by installing a smaller diameter main fuel jet in the
carburetor and readjusting the pilot screw. If you always operate the engine at altitudes higher than
5000 feet (1500 meters) above sea level, have an authorized generator dealer perform this
carburetor modification.
Even with suitable carburetor jetting, engine horsepower will decrease approximately 3.5% for
each 1000 foot (300 meter) increase in altitude. The effect of altitude on horsepower will be greater
than this if no carburetor modification is made.
NOTICE
If a engine jetted for high altitude is used at a lower altitude, the lean air fuel mixture will
reduce performance and may over-heat and seriously damage the engine.

4. PRE-OPERATION CHECK

1) Engine oil
NOTICE
Engine oil is a major factor affecting engine performance and service life. Non-detergent
and 2-stroke engine oils will damage the engine and are not recommended.
Check the oil level BEFORE EACH USE with the generator on a level surface with the engine
stopped.
Use 4-stroke oil, or equivalent high detergent, premium quality motor oil certified to meet or exceed
U.S. automobile manufacturer's requirements for Service Classification SG, SF/CC, CD. Motor oils
classified SG, SF/CC, CD will show this designation on the container.
SAE 10W-30 is recommended for general temperature use. Other viscosities shown in the chart
may be used when the average temperature in your area is within the indicated range.
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