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EMISSIONS SERVICE BULLETIN
Ref No. 10-01-R2
Issued in: Nov. 2010
To:
All RedMax Distributors and Dealers
Subject:
Emission Carburetor: Low Speed/ High Speed Mixture Needle and
Altitude Adjustment Procedures
Emissions Carburetor:
Walbro-Model: WYA- 67A - PART # 848-F0G-8101 (511354201)
PRODUCT MODEL
ENGINE SERIAL NUMBER
Hedge Trimmer:
HTZ 2401(L)/ HTZ 2460(L)
CHTZ 2401(L)/ CHTZ 2460(L)
From:
All units listed with above carburetor models.
The carburetors on the listed model have been factory preset to C.A.R.B. Tier III and E.P.A Phase II
emissions regulations. The
Idle-speed
adjustment is controlled by idle speed throttle valve screw.
The HIGH-speed and Low-speed mixture needles have been preset and sealed to insure compliance with
emission regulations. The
Low-speed Fuel mixture needle
adjustment controls the Fuel/ Air mixture at
idle and mid-range engine speeds. The
High-speed Fuel mixture needle
1. REQUIRED TOOLS
adjustment controls the Fuel/Air
mixture at wide open throttle (WOT) speed. Extended operation above 4000 ft, or after carburetor rebuild,
requires readjustment of idle screw and mixture needles to insure the engine continues to comply with
C.A.R.B, and E.P.A, emission regulations.
Carburetor adjustment screw driver 2.5 mm flat tip, Limiter cap removal tool, Electronic digital
tachometer with sensitivity capable to within 10 RPM increments, and Two (2) Limiter caps.
WARNING!!! DANGER!!!
Always operate unit in a well ventilated and clear work area. Keep hands clear of the cutting
blades during adjustment otherwise serious bodily injury may occur.
2. PRE - ADJUSTMENT CHECK LIST
IMPORTANT: Before performing carburetor adjustment, the following areas must be inspected
and in good working order.
●
Correct spark plug set to specified gap must be used.
Spark Plug: NGK-CMR7H Gap:
●
Standard cutting blades must be installed properly.
0.026 inch (0.65 mm)
●
The air filter must be clean and properly installed.
●
The carburetor and carburetor insulator block screws must be tight.
●
The fuel filter must be clean and properly installed.
●
The muffler spark arrestor screen and exhaust port must be clear
of carbon.
●
The fuel must be fresh (> 89 Octane or higher: RON+MON/ 2) and
properly mixed at 50:1 ratio with RedMax or (ISO-L-EGD/ JASO
FD) registered
2-stroke oil
.
0.026 in
（
0.65 mm
）
Cutting Blades
