English
Adjusting the Carburetor
Basic information
The carburetor comes from the factory with a standard setting.
The carburetor has been adjusted for optimum performance and fuel efficiency in all operating states.
The adjusting screws on this carburetor can only be set within narrow limits.
Standard setting
H |
| H |
|
1/2 | L | L | |
| 1/4 | ||
| 171BA019 KN | ||
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NSwitch off engine
NCheck the air filter – clean or replace it if necessary.
NCheck the spark arresting screen in the muffler (present only in some countries) – clean or replace it if necessary.
NTurn the high speed screw (H) counterclockwise as far as possible (max. 1/2 turn)
NTurn the low speed screw (L) clockwise – as far as possible – then back off 1/4 turn.
Setting the idle speed
H | L | LA |
1/2 | L | |
| 1/4 | |
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| 171BA020 KN |
Engine stops when idling
NSet the low speed screw (L) so that it is 1/4 turn open.
NTurn the idle speed adjusting screw (LA) clockwise until the saw chain begins to run – then turn it back 1/4 turn.
Saw chain rotates at idle speed
NSet the low speed screw (L) so that it is 1/4 turn open.
NTurn the idle speed screw (LA) counterclockwise until the chain stops running – then turn another 1/4 turn in the same direction.
If the saw chain continues to keep rotating in idle even after adjustment, have it checked by a servicing dealer.
Speed erratic when idling; poor acceleration (despite low speed screw = 1/4)
H | L | LA |
1/2 | L | |
| 1/4 | |
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| 171BA020 KN |
Idle setting is too lean –
NTurn the low speed screw (L) counterclockwise until the engine runs and accelerates smoothly – but no further than the stop
Whenever the low speed screw (L) has been adjusted, at least one adjustment must also be made on the idle speed adjusting screw (LA).
Correcting the carburetor setting for use at high altitudes
The setting may have to be marginally corrected if engine performance is unsatisfactory at high altitudes.
NCheck the standard setting N Let the engine warm up
NTurn the high speed screw (H) clockwise (leaner) – max. up to the stop
If you make the setting too lean it will increase the risk of engine
damage through lack of lubrication and overheating.
38 | MS 880 |