V4.0
302cc OHV Winter Gas Engine
8717621
Visit www.princessauto.com for more information
9
MODIFYING THE CARBURETOR FOR HIGH ALTITUDES
At high altitudes, the standard air-fuel mixture is too rich, causing increased fuel consumption and decreased
performance. A rich mixture will also foul the spark plug and cause hard starting.
A qualified technician can improve high altitude performance with certain modifications. Have your carburetor modified if
the engine will routinely be operated at altitudes above 5,000 ft (1,500 m). Even with carburetor modification, engine
power will decrease about 3.5% for each 1,000 ft (305 m) increase in altitude. The effect of altitude on power will be
greater than this is if no modification is made.
NOTICE! When the carburetor has been modified for high altitude operation, the air fuel mixture will be too lean for
low altitude use. Operation at altitudes below 5,000 ft (1,500 m) may cause the engine to overheat and result in
serious engine damage. When using this engine at low altitudes, have a qualified technician return the carburetor
to original factory specifications.
CLEANING THE SEDIMENT CUP
CAUTION! Wear latex or rubber gloves when working on the sediment cup. The cup may contain fuel that will cause
skin irritation. Prolonged and repeated exposure to fuel on skin may result in dry, cracked skin.
1. Switch the fuel valve to the OFF position.
2. Remove the fuel sediment cup, screw and o-ring.
3. Clean the sediment cup with a non-flammable solvent or detergent and rinse. Allow to dry.
a. Some chemicals will damage the o-ring material. Check for compatibility or simply replace the o-ring.
4. Reassemble the sediment cup and o-ring.
5. Switch the fuel valve to the ON position and check for leaks. Replace the o-ring if the installation is correct, but fuel
still leaks from the cup.
CLEANING
WARNING! Use only a nonflammable solvent, not gasoline, to clean engine parts. Keep all sources of ignition away
from fuel related parts. Fumes are flammable and may catch fire, causing a burn injury.
NOTICE! Do not clean the engine’s exterior with a garden hose or pressure washer. Water can enter the engine
through the air filter or muffler opening and damage the cylinder.
1. Allow engine to cool for at least half an hour before cleaning.
2. Clean all exterior surfaces.
3. Touch up any damaged paint.
4. Coat other areas that may rust with a light film of oil.
ENGINE OIL
NOTICE! Engine oil is a major factor affecting engine performance and service life. Non-detergent and 2-stroke
engine oils will damage a 4-stroke engine and are not recommended.
High-quality detergent engine oils are acceptable if the (API) performance rating is SF, SG, SH, SJ or higher. Always
check the API service label on the oil container for the performance rating.
1. Check the oil level before each use with a cool engine that is level.
2. Use 4-stroke motor oil that meets or exceeds the requirements for API
(American Petroleum Institute) service classification SF.
Always check the
API Service label on the oil container to be sure it includes the letters SF.
3. Do not use special additives.
4. SAE 10W-30 is recommended for general, all-temperature use. Other
viscosities shown on the chart may be used when the average temperature
in your area is within the indicated range (Fig. 5).
5. Above 27°C (80°F), using 10W-30 oil may increase oil consumption.
Check the oil level more often.
6. Below 4°C (40°F), using SAE 30 oil will cause hard starting.
Fig. 5
