Echo CS-450P Instruction Manual

Also see for CS-450P: Operator's manual Instruction manual Instruction manual

Echo CS-450P Instruction Manual Manual pdf 25 page image

25 CS-450PCARBURETOR ADJUSTMENTEvery unit is run at the factory and the carburetoris set in compliance with Emission Regulations. Inaddition, the carburetor is equipped with “H” (HighSpeed) and “L” (Low Speed) needle adjustmentlimiters that prevent settings outside acceptablelimits.1. Before adjusting carburetor clean or replace airfilter and muffler “Spark Arrestor Screen”.2. Make sure the bar and chain are properly ad-justed.3. Start engine and run several minutes to bring tooperating temperature. Flash choke twice duringwarm-up to clear any air from the fuel system.4. Stop engine.Turn “H” speed needle counterclockwise (CCW)to stop.Turn “L” speed needle midway between fullclockwise (CW) stop and CCW stop.5. Idle Speed Adjustment:• Start engine, turn “Idle” speed adjustmentscrew CW until the saw chain begins to turn,then turn screw out CCW until the saw chainstops turning.Turn screw out, CCW, an additional 1/4 turn.6. Accelerate to full throttle for 2 - 3 seconds toclear any excess fuel in the engine, then returnto idle.Accelerate engine to full throttle to check forsmooth transition from idle to high speed.If engine hesitates turn “L” needle CCW 1/8 turnand repeat acceleration.Continue adjustment until smooth accelerationresults.7. Check idle speed and reset if necessary asdescribed in item 5. If a tachometer is availableidle speed should be set to 2700 RPM.WARNINGCutting attachment must not move when unitis idling.CAUTIONWhen starting, idling adjustment speedshould be adjusted not to rotate the sawchain. Correct idle speed is adjusted 2700RPM. Or 1/4 turn CCW from the point thechain stops moving.When you experience trouble with thecarburetor, contact your dealer.Idle adjusting screwLow speed needle (L) High speed needle (H)High Altitude OperationThis engine has been factory adjusted to maintainsatisfactory starting, emission, and durabilityperformance up to 1100 feet above sea level (ASL)(96.0 kPa). To maintain proper engine operationand emission compliance above 1100 feet ASLthe carburetor may need to be adjusted by anauthorized ECHO service dealer.IMPORTANTIf the engine is adjusted for operation above1100 feet ASL, the carburetor must bereadjusted when operating the engine below1100 feet ASL, otherwise severe engine damagemay result.Engine Break-InNew engines must be operated a minimum dura-tion of two tanks of fuel break-in before carbure-tor adjustments can be made. During the break-inperiod your engine performance will increase andexhaust emissions will stabilize. Idle speed canbe adjusted as required.