MTD
Gas Walk-Behind Mower

Model #12A-948K299 Official MTD lawn mower

Here are the diagrams and repair parts for MTD 12A-948K299 lawn mower, as well as links to manuals and error code tables, if available.

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  • Click a diagram to see the parts shown on that diagram.
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Not all parts are shown on the diagrams—those parts are labeled NI, for “not illustrated”.

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For DIY troubleshooting advice and repair guides, visit our repair help section.

Owner’s manual

    Showing 10 of 96 parts

    Lawn Mower 21-in Deck Mulching Blade#16

    Handle/deck/chute Diagram

    Lawn mower 21-in deck mulching blade

    Part #942-0741A
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    $23.00 | 
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    MSRP: $31.00
    Lawn & Garden Equipment Lock Nut, 5/16-18#3

    Handle/deck/chute Diagram

    Lawn & garden equipment lock nut, 5/16-18

    Part #712-04063
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    In Stock
    $3.19 | 
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    MSRP: $4.90
    Lawn Mower Blade Support#18

    Handle/deck/chute Diagram

    Lawn mower blade support

    Part #736-0524B
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    Phone Price: $6.39
    Lawn Mower Handle Knob#30

    Handle/deck/chute Diagram

    Lawn mower handle knob

    Part #720-04072A
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    $5.79 | 
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    MSRP: $8.50
    Lawn Tractor Screw, 1/4-20 x 5/8-in#35

    Drive/wheels Diagram

    Lawn tractor screw, 1/4-20 x 5/8-in

    Part #710-1652
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    Lawn & Garden Equipment Hex Head Screw#22

    Handle/deck/chute Diagram

    In Stock
    $7.99 | 
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    Lawn & Garden Equipment Wing Nut#42

    Handle/deck/chute Diagram

    Lawn & garden equipment wing nut

    Part #712-0397A
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    Lawn Mower Ground Drive Belt#29

    Handle/deck/chute Diagram

    Lawn mower ground drive belt

    Part #954-0460
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    Phone Price: $28.49
    Lawn Mower Lower Handle#12

    Handle/deck/chute Diagram

    In Stock
    $50.89 | 
    9% OFF 
    Phone Price: $55.89
    Lawn Mower Height Adjuster Lever#5

    Drive/wheels Diagram

    Lawn mower height adjuster lever

    Part #732-0803A
    This item is not returnable
    In Stock
    $12.94

    Symptoms for gas walk-behind mowers

    Choose a symptom to see related walk-behind mower repairs.

    Main causes: uneven wheel height settings, damaged wheel, dull or damaged cutting blade
    Main causes: damaged cutting blade, loose cutting blade, damaged flywheel key, engine needs tune up
    Main causes: dirty carburetor, bad spark plug, clogged air filter, engine choke problems, clogged gas cap vent
    Main causes: engine needs tune up, dirty or clogged carburetor, damaged flywheel key
    Main causes: drive control cable failure, worn or broken drive belt, bad transmission, broken drive wheel
    Main causes: stale gas, engine needs tune up, bad spark plug, dead battery, bad recoil starter, faulty safety switch, bad ignition coil

    Repair guides for gas walk-behind mowers

    These step-by-step repair guides will help you safely fix what’s broken on your walk-behind lawn mower.

    March 1, 2016
    By Lyle Weischwill
    How to replace a lawn mower blade

    Check your lawn mower blade regularly and replaced it if it's bent or damaged.

    Repair difficulty
    Time required
     15 minutes or less
    How to replace a lawn mower ignition coil on an OHV engine

    Replace the ignition coil if it isn't sending electric current to the spark plug when you pull the recoil starter rope.

    Repair difficulty
    Time required
     30 minutes or less
    How to replace a lawn mower flywheel key on a flathead engine

    When you hit a hard object with your mower, the flywheel can shear to protect more expensive components. Learn how to replace this tiny but essential part.

    Repair difficulty
    Time required
     45 minutes or less

    Articles and videos common to all walk-behind mowers

    Use the advice and tips in these articles and videos to get the most out of your walk-behind lawn mower.

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    August 5, 2022

    Introducing new technical repair content that we’re developing for the Sears Technical Institute

    By Lyle Weischwill

    Learn about Sears Technical Institute and the advanced technical content being developed for aspiring appliance techs.

    June 29, 2022

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    Get answers to frequently asked questions about Sears and Sears PartsDirect.