Snapper NZM21521KWV User Manual (English)

Questions and Answers:

W
wadelindaJul 29, 2025
What to do if my Snapper Lawn Mower engine will not start?
- A
  Andrew JonesJul 30, 2025
  If your Snapper Lawn Mower engine will not start, make sure the blade engagement switch is in the “OFF” position. Also, ensure the parking brake is set, and you are seated in the operator's seat. Check that the motion controls are in the Neutral Lock Position. Verify the fuel tank isn't empty and fill it with fresh fuel if needed. If the engine needs choking, move the choke control to the “CHOKE” position. Check that the spark plug wire is connected to the spark plug. Finally, ensure the battery isn't weak or dead; service the battery if necessary. If all else fails, it could be a faulty parking brake, blade, or ignition switch, and you should contact an authorized SNAPPER dealer.
M
Mary Torres MDAug 3, 2025
Why is my Snapper Lawn Mower engine losing power?
- D
  Denise HintonAug 3, 2025
  If your Snapper Lawn Mower engine loses power, try lessening the load on the engine. Clean or replace the engine air pre-cleaner or air cleaner if they are dirty. Ensure the engine oil level is at the proper level by filling it as needed. Clean the engine cooling fins and air intake screen of any debris. Service the spark plug if it's faulty. Lastly, drain and clean the fuel system to remove any water, debris, or stale fuel.
N
Nancy WarrenAug 8, 2025
What to do if my Snapper NZM21521KWV Lawn Mower engine stalls after running?
- J
  jordanloriAug 8, 2025
  If your Snapper Lawn Mower engine stalls after running, make sure you are sitting in the operator’s seat. Move the choke control to the “OFF” position if it's in the “CHOKE” position. Refill the fuel tank to the proper level if it is empty. Clean the engine air pre-cleaner and/or air cleaner if they are dirty. Service the spark plug if it is defective or the gap is set improperly. Replace the fuel filter if it is clogged. Finally, drain and clean the fuel system to remove any water, debris, or stale fuel.
C
carlos97Aug 13, 2025
How to troubleshoot a Snapper NZM21521KWV when the starter will not crank the engine?
- J
  johnathan95Aug 13, 2025
  If the starter of your Snapper Lawn Mower will not crank the engine, service the battery. Replace the fuse if it is blown. Clean and check electrical connections for good contact if they are loose or corroded. If these steps do not resolve the issue, contact an authorized SNAPPER dealer as the ignition switch may be defective.
A
Alexis ArmstrongAug 18, 2025
Why is my Snapper NZM21521KWV experiencing excessive vibration?
- P
  Pamela LaneAug 18, 2025
  If your Snapper Lawn Mower is experiencing excessive vibration, service the mower blades if they are damaged or bent. Service and tighten any loose blade components. Inspect all belts and pulleys for worn or damaged components. If equipped, replace any loose or missing air lifts and tighten them to the proper torque.
N
nwillisAug 23, 2025
How to stop a Snapper Lawn Mower engine from backfiring?
- L
  Leslie KrauseAug 23, 2025
  To prevent your Snapper Lawn Mower engine from backfiring when turned to “STOP,” set the throttle control to “SLOW” and allow the engine to idle. Then, turn the key to “OFF.”

Snapper NZM21521KWV Specifications

General

Engine Type	Briggs & Stratton
Engine Displacement	163 cc
Drive Type	Self-Propelled
Deck Material	Steel
Start Type	Recoil
Mulching Capability	Yes
Rear Bag	Yes
Speed Control	Variable
Cutting Width	21 inches
Cutting Height	1.25 - 3.75 in
Engine	Briggs & Stratton® EXi725 Series Engine
Weight	82 lbs

Summary

IMPORTANT SAFETY INSTRUCTIONS

Child Safety and Tip-Over Prevention

Ensures child safety in mowing areas and provides guidelines to prevent tip-over accidents on slopes.

Safe Fuel Handling and Preparation

Precautions for safe refueling, storage, and pre-operation checks.

Operation and Maintenance Safety

Essential safety practices for operating and maintaining the machine.

Section 1 - FAMILIARIZATION

Introduction and Nomenclature

Overview of the manual and identification of machine parts and controls.

Section 2 – SAFETY MESSAGES AND SYMBOLS

Safety Symbols and Control Operations

Understanding safety symbols, control functions, and ignition switch operation.

Starting, Operating, and Stopping Procedures

Step-by-step guide to starting, operating, and stopping the machine and its controls.

Section 3 - OPERATING INSTRUCTIONS

Pre-Start Checklist and Blade Operation

Essential checks before starting and how to operate the blade switch.

Seat and Deck Height Adjustments

Procedures for adjusting the operator's seat and mower deck height.

Engine Starting and Brake Procedures

Steps for starting the engine, using the parking brake, and roll release.

Stopping Engine and Blades

Instructions for safely shutting down the engine and disengaging mower blades.

Driving and Stopping Machine Controls

Instructions for operating motion control levers and safely stopping the machine.

Safety Interlock System Checks

Checks to ensure all safety interlock devices are functioning correctly.

Section 4 - MAINTENANCE

Initial Maintenance (First 5 Hours)

Initial maintenance tasks to be performed after the first 5 operating hours.

Routine Engine and Blade Checks

Procedures for changing engine oil and inspecting mower blades.

Drive Belt and 25-Hour Service

Checking drive belts and performing 25-hour engine and mower component services.

Lubrication and Annual Service

Lubrication points, pre-operation cleaning, and end-of-season maintenance.

Fuel Filter and Deck Removal

Procedures for replacing the fuel filter and removing the mower deck.

Hydraulic Fluid Filter Maintenance

Information on hydraulic fluid filter replacement and maintenance.

Section 5 - ADJUSTMENTS & REPAIR

Neutral Position Adjustments

Procedure to adjust motion control levers for proper neutral stopping.

Mower Deck Levelness Adjustment

Adjusting the mower deck for proper side-to-side and front-to-rear levelness.

Parking Brake and Traction Belt Adjustments

Adjusting the parking brake and checking traction belt tension.

Belt Replacement and Clutch Adjustment

Steps for replacing belts and adjusting the blade brake/electric clutch.

Tracking and Drive Belt Replacement

Adjusting machine tracking and replacing the mower drive belt.

Blade Replacement and Sharpening

Procedures for replacing, inspecting wear limits, and sharpening mower blades.

Battery Service and Testing

Steps for battery removal, installation, service, testing, and preparation.

Spindle Bearing and Hydraulic System Maintenance

Procedures for replacing spindle bearings and purging the hydraulic system.

TROUBLESHOOTING

Engine Starting and Power Issues

Diagnosing and resolving engine starting, stalling, and power loss problems.

Machine Movement and Cutting Problems

Troubleshooting issues with machine movement, traction, cutting, and grass discharge.

2 YEAR LIMITED WARRANTY

Warranty Limitations and Disclaimers

Details limitations and exclusions of implied warranties.

PRIMARY MAINTENANCE

Importance of Air Cleaner Service

Explains the impact of a dirty air cleaner on engine performance.

Filter Care and External Cleaning

Guidance on cleaning air filters and the importance of external machine cleaning.

Fuel and Lubrication Best Practices

Advice on using clean fuel and ensuring proper engine lubrication and oil levels.

Engine Oil and Fuel Mixture Procedures

Instructions for changing oil in 4-cycle engines and mixing fuel for 2-cycle engines.

Starting Checklist and Safety Reminders

A comprehensive checklist for starting the engine and machine, with safety reminders.

Related product manuals

Snapper NZM19480KWV, NZM21520KWV

41 pages

NZM19483KWV, NZM21523KWV, NZM25523KWV, NZM25613KWV, NZM27613KH

78 pages

Snapper NZMJ23521KH, NZMJ25611KH