English / USA
Standard Setting
Adjusting Idle Speed
It is usually necessary to change the
setting of the idle speed screw (LA)
after every correction to the low speed
screw (L).
L
H L
Fine tuning for operation at high
altitude
A slight correction of the setting may be
necessary if engine power is not
satisfactory:
LA
:
:
Shut off the engine.
Engine stops while idling
:
:
:
Check standard setting.
Warm up the engine.
Turn the high speed screw (H)
clockwise (leaner) – no further than
stop.
Check the air filter and clean or
:
Turn the idle speed screw (LA)
clockwise until the engine runs
smoothly.
replace if necessary.
:
:
Check the spark arresting screen (if
fitted) in the muffler and clean or
replace if necessary.
Erratic idling behavior, engine stalls
even after re-adjusting LA screw,
poor acceleration
Carefuly turn both adjusting screws
If the setting is too lean, there is a
risk of engine damage due to
insufficient lubrication and
overheating.
counterclockwise as far as stop:
High speed screw (H) is now open
Idle setting is too lean:
1/4
turn
:
Turn low speed screw (L)
Low speed screw (L) is now open
counterclockwise – no further than
stop – until the engine runs and
accelerates smoothly.
1/4
turn
:
Start and warm up the engine.
Erratic idling behavior
Idle setting is too rich:
Turn low speed screw (L) clockwise
– no further than stop – until the
:
engine runs and still accelerates
smoothly.
BR 420
21
| Categories | Blower Vacuum and Sweeper Manuals, STIHL Blower and Vacuum Manuals |
|---|---|
| Tags | STIHL BR 420 |
| Download File |
|
| Language | English, Español |
| Product Brand | STIHL. Stihl Inc, USA - Corporate phone: (757) 486-9100. International Support Information: http://stihl.com Email: info@stihl.com, Blower Vacuum |
| Document File Type | |
| Publisher | stihl.com |
| Wikipedia's Page | Stihl |
| Copyright | Attribution Non-commercial |
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