MODIFYING THE CARBURETOR FOR HIGH
ALTITUDES
At high altitude, 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 (1,524 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
engine 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 (1,524
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. Some chemicals
will damage the o-ring material. Check for compatibility
or 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. FIGURE 5.
8871626 GAS ENGINE FOR SNOWBLOWER V1.0
Assistance available at www.princessauto.com or 1-800-665-8685 Page 16