Echo PB-620ST - Manual (Page 20)

20
Carburetor adjustment
Engine Break-In
New engines must be operated for a minimum duration of two tanks of
fuel before carburetor adjustments can be made. During the break-in
period your engine performance will increase and exhaust emissions
will stabilize. Idle speed can be adjusted as required.
High Altitude Operation
This engine has been factory adjusted to maintain satisfactory starting,
emission, and durability performance up to 1,100 feet above sea level
(ASL) (96.0 kPa). To maintain proper engine operation and emission
compliance above 1,100 feet ASL the carburetor may need to be ad-
justed by an authorized ECHO service dealer.
IMPORTANT
If the engine is adjusted for operation above 1,100 feet ASL, the
carburetor must be re-adjusted when operating the engine below
1,100 feet ASL, otherwise severe engine damage may result..
Level 2.
Tools required: Screwdriver, tachometer (Echo P/N 99051130017)
Parts required: None.
NOTE
Do not adjust carburetor unless necessary. If you have difficulty,
see your ECHO dealer.
Adjustment Screws
Idle Speed (A) Control throttle opening at idle.
Low (LO) Speed (B) Controls amount of fuel at low speed and
supplementary fuel for smooth progression from
idle to high speed.
High (HI) Speed (C) Controls amount of fuel at full throttle
Before Adjustment
Check that:
•
Air filter is clean and properly installed.
• Spark arrestor screen and muffler are free of carbon.
• Blower pipes are installed.
A
C
B