Craftsman Craftsman M110 140cc 21" Push Gas Lawn Mower MECH-WONT-START Error Fix: Engine Will Not Start

Error code MECH-WONT-START on the Craftsman Craftsman M110 140cc 21" Push Gas Lawn Mower means: Engine Will Not Start. The push mower engine does not start when the pull cord is pulled or the electric start button is pressed. This is the #1 mower complaint and is usually caused by fuel or spark issues. Check in this order: (1) FUEL — is there fresh gas in the tank? Gasoline older than 30 days without stabilizer degrades, forming varnish that clogs the carburetor. Drain old fuel and refill with fresh 87+ octane gas. For stored mowers, old fuel is the #1 cause of no-start. (2) SPARK PLUG — remove and inspect. A fouled (black/oily), cracked, or worn plug prevents ignition. Replace annually ($3-$5). Check the gap (typically 0.030"). Test for spark by grounding the plug against the engine block while pulling the cord — a blue spark should be visible. (3) AIR FILTER — a severely clogged filter prevents air intake. Remove and inspect. Replace paper filters; clean foam filters with soap and water, re-oil. (4) CHOKE — set to FULL/CLOSED for cold starts. Move to RUN/OPEN after engine warms up. (5) BAIL LEVER — the bail lever (operator presence control) must be held against the handlebar while pulling the cord. (6) OIL LEVEL — some Craftsman mowers have a low-oil shutdown sensor. Check oil and fill to the FULL mark. (7) CARBURETOR — if stale fuel sat in the carburetor, it needs cleaning. Remove the bowl, clear jets with carburetor cleaner and compressed air. A carburetor rebuild kit costs $8-$15.

The most successful fix is "Clean Carburetor and Replace Air Filter" (medium difficulty, ~45 minutes). Estimated DIY cost: $10-$20. HomeMD has 2 community-ranked fixes for this error.

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Yes — the top-ranked community fix ("Clean Carburetor and Replace Air Filter") is rated medium difficulty and takes about 45 minutes. Tools needed: Socket wrench set, Carburetor cleaner spray, Compressed air canister, Screwdriver set.

DIY cost: $10-$20. Professional repair typically costs $120-$180. Many homeowners save money by trying the top-ranked community fix first.

The Craftsman Craftsman M110 140cc 21" Push Gas Lawn Mower has 8 other known error codes, including: MECH-FUEL-LEAK (Fuel Leaking from Mower — Fire Hazard), MECH-OIL-LEAK (Engine Oil Leak or Excessive Oil Consumption), MECH-PULL-CORD (Pull Cord Breaks, Sticks, or Will Not Retract), MECH-RUNS-ROUGH (Engine Surges, Sputters, or Runs Rough), MECH-SELF-PROPEL (Self-Propel Drive Not Working or Weak), and 3 more.

Error code MECH-WONT-START also appears on 9 other Craftsman models: Craftsman B210 27cc 2-Cycle Gas Leaf Blower (210 MPH), Craftsman CMXGWAS021021 3000 PSI 2.3 GPM Gas Pressure Washer, Craftsman R105 30" 10.5 HP Gear-Drive Rear Engine Riding Mower, Craftsman T110 42" 17.5 HP Briggs & Stratton Single-Cylinder Riding Lawn Tractor, M270 21 in 159 cc 3-in-1 Self-Propelled Gas Push Mower, S180 42cc Chainsaw, and 3 more. The fix may vary by model, so check each model's specific page for tailored repair steps.