RedMax TR2350 - User Manual

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EMISSIONS SERVICE BULLETIN
Ref No. 12-01R
Issued in: Jan. 2012
To: All RedMax Distributors and Dealers
Subject: Emission Carburetor: Low Speed Mixture Needle
and Altitude Adjustment Procedures (Fixed Main Jet)
Emissions Carburetor: Walbro-Model: WYL- 221 PART # 521600901 (848E488100)
PRODUCT MODEL
ENGINE SERIAL NUMBER
Brush-cutter:
TR2350
From:
All units listed with above carburetor model
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 Low-speed mixture needles has 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 wide open throttle (WOT) speed operation is controlled by Fixed Main Jet.
Extended operation above 4000 ft, or after carburetor rebuild, requires readjustment of idle screw and
mixture needle to insure the engine continues to comply with C.A.R.B, and E.P.A, emission regulations.
1. REQUIRED TOOLS
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 One (1) Limiter cap.
WARNING!!! DANGER!!!
Always operate unit in a well ventilated and clear work area. Keep hands clear of moving,
rotating, cutting attachment, or components 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-BPMR7Y Gap: 0.026 inch (0.65 mm)
● Standard nylon head must be installed with 7 inches (180 mm)
of line exposed on both sides.
● 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）

Summary

Required Tools for Carburetor Adjustment

Pre-Adjustment Checklist for Carburetor Service

Carburetor Adjustment Procedures

Carburetor Adjustment With Limiter Cap Installed

Procedure for adjusting carburetor with limiter caps in place, including engine warm-up and RPM settings.

Carburetor Adjustment With Limiter Cap Removed

Steps for removing limiter caps and performing initial adjustments for starting and idle conditions.

Low Speed Mixture Needle Adjustment

Detailed steps for adjusting the low-speed mixture needle to achieve optimal idle and lean drop-off.

Checking Maximum RPM and Final Verification

Procedure to check and verify engine RPM at wide open throttle and idle after adjustments.

Gasoline Requirements for RedMax Engines

Overview

1. Function Description
2. Important Technical Specifications
3. Usage Features
4. Maintenance Features

This document outlines the emissions service bulletin for RedMax brush-cutters, specifically the TR2350 model equipped with the Walbro WYL-221 carburetor (Part #521600901, 848E488100). It details the procedures for adjusting the low-speed mixture needle and performing altitude adjustments, emphasizing compliance with C.A.R.B. Tier III and E.P.A Phase II emissions regulations.

Function Description

The RedMax TR2350 brush-cutter is designed for efficient cutting tasks, powered by a 2-stroke engine. The carburetor, a Walbro WYL-221, is factory preset for emissions compliance. The bulletin focuses on maintaining this compliance through proper adjustment of the idle-speed throttle valve screw, low-speed mixture needle, and ensuring the fixed main jet operates correctly. The low-speed mixture needle controls the fuel/air mixture at idle and mid-range engine speeds, while the fixed main jet manages wide-open throttle (WOT) operation. Adjustments are necessary after extended operation above 4000 ft or after a carburetor rebuild to ensure continued emissions compliance.

Important Technical Specifications

• Model: RedMax TR2350 Brush-cutter
• Carburetor Model: Walbro WYL-221
• Carburetor Part Number: 521600901 (848E488100)
• Emissions Compliance: C.A.R.B. Tier III and E.P.A Phase II
• Spark Plug: NGK-BPMR7Y
• Spark Plug Gap: 0.026 inch (0.65 mm)
• Standard Nylon Head Line Exposure: 7 inches (180 mm) on both sides
• Fuel Requirements: Minimum 89 Octane (RON+MON/2) or higher, unleaded (lead-free) gasoline.
• Ethanol Content: Maximum 10% Ethanol (grain alcohol) or up to 15% MTBE (Methyl tertiary-butyl ether). Methanol (Wood Alcohol) is NOT approved.
• Fuel/Oil Mixture Ratio: 50:1 with RedMax or (ISO-L-EGD/JASO FD) registered 2-stroke oil.
• Idle Speed (Initial Adjustment): 3000 RPM +/- 200 RPM (range 2800-3200 RPM)
• Wide Open Throttle (WOT) Speed (Initial Adjustment): 7500-8500 RPM
• Idle Speed (Low Speed Mixture Needle Adjustment): 3800 RPM +/- 50 RPM (stable range)
• Rich Down Adjustment: 600-800 RPM reduction to 3000 RPM idle speed after lean drop off.
• Minimum WOT Engine Speed: 7500 RPM

Usage Features

The device is intended for brush-cutting applications. Proper operation requires adherence to specific fuel and maintenance guidelines.

• Fuel Quality: Use fresh gasoline with a minimum of 89 octane. Low octane fuel can lead to engine overheating, detonation (knock), piston seizures, and major internal engine damage, which is not covered by warranty.
• Oil Mixture: A 50:1 ratio of RedMax or ISO-L-EGD/JASO FD registered 2-stroke oil with gasoline is critical for lubrication.
• Altitude Adjustment: The carburetor may require readjustment after extended operation above 4000 ft to maintain optimal performance and emissions compliance.
• Warm-up Procedure: Before any adjustments, the engine must be warmed up for a minimum of 3.5 minutes, alternating between WOT for 1 minute and idle for 10 seconds.
• Safety: Always operate the unit in a well-ventilated and clear work area. Keep hands clear of moving, rotating, cutting attachments, or components during adjustment to prevent serious bodily injury.

Maintenance Features

Regular maintenance is crucial for the brush-cutter's performance and longevity, as well as for emissions compliance.

• Required Tools for Adjustment:
  • Carburetor adjustment screwdriver (2.5 mm flat tip)
  • Limiter cap removal tool
  • Electronic digital tachometer (sensitivity within 10 RPM increments)
  • One (1) Limiter cap
• Pre-Adjustment Checklist:
  • Spark Plug: Ensure the correct spark plug (NGK-BPMR7Y) is used and gapped correctly (0.026 inch / 0.65 mm).
  • Cutting Head: Standard nylon head with 7 inches (180 mm) of line exposed on both sides must be installed.
  • Air Filter: Must be clean and properly installed.
  • Carburetor and Insulator Block: Screws must be tight.
  • Fuel Filter: Must be clean and properly installed.
  • Muffler: Spark arrestor screen and exhaust port must be clear of carbon.
  • Fuel: Use fresh, properly mixed fuel (≥ 89 Octane, 50:1 ratio).
• Carburetor Adjustment Procedures:
  • Idle Speed Adjustment (with limiter cap installed): Adjust the idle speed throttle valve screw (A) to achieve 3000 RPM +/- 200 RPM (2800-3200 RPM idle) and 7500-8500 RPM at WOT.
  • Low Speed Limiter Cap Removal: Use the limiter cap removal tool to extract the cap from the low-speed mixture needle hole.
  • Initial Start Settings (if original needle settings NOT disturbed): Turn throttle valve adjust screw (A) IN clockwise (CW) 1.5 turns. Turn low-speed mixture needle (B) OUT counterclockwise (CCW) 1/8 turn.
  • Initial Start Settings (if original settings WERE disturbed): Turn throttle valve adjust screw (A) counterclockwise (CCW) until it touches the throttle plate stop, then turn it in clockwise (CW) 7 turns. Turn low-speed mixture needle (B) counterclockwise (CCW) completely out until a clicking sound is heard, then turn it in clockwise (CW) 12-1/8 turns.
  • Low Speed Mixture Needle (B) Adjustment: Set engine idle speed at 3800 +/- 50 RPM. Adjust the low-speed mixture needle (B) to reach maximum engine speed AT IDLE just before lean drop-off. If idle speed at lean drop-off is higher than 3800 RPM, adjust idle speed throttle valve screw (A) counterclockwise (CCW) down 500 RPM. Repeat until maximum lean drop-off speed is reached and idle speed is stable at 3800 +/- 50 RPM. Then, turn the low-speed mixture needle (B) counterclockwise (CCW) in 1/8th turn increments to "Rich Down" the mixture 600-800 RPM, reducing engine speed AT IDLE to 3000 RPM. Allow 20 seconds for stabilization after each 1/8th turn.
  • Checking Maximum RPM: Accelerate to WOT and ensure minimum engine speed is 7500 RPM. After checking, stop the engine.
  • Limiter Cap Installation: Insert a new limiter cap into the low-speed mixture needle hole to prevent tampering and ensure compliance.
  • Final Verification: Re-start the engine and verify idle speed (2800-3200 RPM) and WOT speed (7500-8500 RPM) are within range, and the engine idles and accelerates smoothly.
• Troubleshooting: If problems persist, check the carburetor for dirt, varnish, gum, moisture, and corrosion contamination.
• Tampering Warning: Carburetor adjustments with caps removed must only be conducted by Authorized Emission Certified Servicing Dealers. Knowingly removing or rendering inoperative any emission control device is a violation of FEDERAL LAW, subject to significant civil penalties.

RedMax TR2350 Specifications

General

Brand	RedMax
Model	TR2350
Category	Brush Cutter
Language	English