RedMax HTZ 2401 Service Bulletin

3/4 Page EMISSIONS SERVICE BULLETIN Ref No. 10-01-R2Issued in: Nov. 2010Start and run the unit to warm up the engine. Engine must be atoperating temperature before completing Low speed mixtureand High speed mixture needle adjustments. Warm up enginefor minimum of 3.5 minutes■Low Speed Mixture Needle (B) Adjustmentby alternating between Wide OpenThrottle (WOT) for 1 minute, then idle for 10 seconds.1) Set engine Idle Speed at 4500 +/- 10 RPM by turning Idlespeed throttle valve screw2) NOW adjust Low speed(A). The engine RPM should be stable inthe 4500 RPM range.mixture needle (B) Clockwise (CW) Leaningor Counter clockwise (CCW) Richening to reach Maximum enginespeed AT IDLE just before lean3) If the idle speed at lean drop of is HIGHER than 4500 rpm. AdjustIdle speeddrop off, where RPM just begins todrop.throttle valve screw4)(A) Counterclockwise (CCW) down500 RPM.Repeat step 2) and 3) as needed using 500 RPM step reduction,until maximum lean drop of speed is reached and speed AT IDLE5) Turnisstable at 4500 +/- 10 RPM.Low speed mixture needle (B) counterclockwise (CCW) in1/8th turn increments and Rich Down the mixture 1400-1600 RPMto reduce engine speed AT IDLE, down to 3000NOTE: Engine speed must be allowed to stabilize a minimum of20 seconds after each 1/8th of a turn adjustment of LowspeedRPM.mixture needle to assure accurate tachometer readings.■Checking Maximum RPMVerifying Engine RPM Using TachometerNOTE: High speed mixture needle adjustments are not required.1) Accelerate engine to Wide Open Throttle (WOT).2) Check the acceleration state of the engine speed, and make surethat the engine speed is 9000 rpm or more.3) If (WOT) engine speed is LOWER than 9000 RPM, turn High speedmixture needle (C) clockwise (CW) 1/8 turns.NOTE: Maximum RPM is controlled less than 10500 RPM byspeed governor in the ignition module.4) After checking WOT RPM, stop the engine. To comply with theEmission regulations, insert new limiter caps in the Low and Highspeed mixture needle holes. Press new limiter caps deep into Lowspeed and High speed mixture needle holes to prevent tampering.5) Re-Start engine and verify engine Idle speed6) Verifyrange from 2800 to3200 RPM.Wide Open Throttle (WOT) engine speed range from 9000 to10500 RPM, and the engine should idle and accelerate smoothly.NOTE: If problem persistsATTENTION !!! IMPORTANT !!!, check carburetor for dirt, varnish,gum, moisture and corrosion contamination .Carburetor adjustments with caps removed must be conducted by Authorized Emission CertifiedServicing Dealers ONLY. The dealer must supply the unit to the customer in the originalconfiguration, using manufacturer’sTAMPERING is a violation of FEDERAL LAW, resulting in significant civil penalties (fines) of up to$25,000 for each violation.carburetor adjustment procedure, which includes having thelimiter caps in place before the unit is put into service . Knowingly removing or renderinginoperative a device, element, or design installed on or in a non-road engine which is incompliance with E.P.A. or C.A.R.B. regulations is classified as TAMPERING.High-speed Needle (C)Low-SpeedNeedle (B)Idle speedThrottle Valve Screw (A)New Limiter CapLimiter Cap ToolIdlingFullThrottle1st Time 2nd Time 3rd TimeAdjustment when engine activated

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