Craftsman S180 42cc Chainsaw MECH-WONT-START Error Fix: Chainsaw Engine Will Not Start

Error code MECH-WONT-START on the Craftsman S180 42cc Chainsaw means: Chainsaw Engine Will Not Start. The chainsaw engine does not start after repeated pull attempts. Craftsman chainsaws (like the S180 with a 42cc 2-cycle engine) require a fuel/oil mix and proper starting procedure. Check in order: (1) FUEL — use fresh 50:1 gas/oil mix (2.6 oz 2-cycle oil per gallon of 87+ octane gas). Pre-mixed fuel is available and eliminates mixing errors. Fuel older than 30 days degrades rapidly in 2-cycle engines. (2) STARTING PROCEDURE — set the choke to FULL, pull the starter cord 3-5 times until the engine pops/fires briefly, then move the choke to HALF, pull again to start, then move to RUN after warmup. Many no-start complaints are simply incorrect choke procedure. (3) FLOODED ENGINE — if you smell raw fuel, the engine is flooded (too much fuel in the cylinder). Set the choke to OFF/RUN, hold the throttle wide open, and pull the cord 5-10 times. Or remove the spark plug, let the fuel evaporate, dry the plug, and reinstall. (4) SPARK PLUG — remove and inspect. Replace if fouled, cracked, or worn. Check gap (typically 0.025"). (5) AIR FILTER — a clogged filter prevents adequate airflow. Clean or replace. (6) FUEL FILTER — the fuel filter sits inside the fuel tank on the end of the fuel line. It clogs with debris. Pull it out through the filler hole with a wire hook and replace. (7) CARBURETOR — stale fuel varnish clogs the tiny jets. Clean or rebuild.

The most successful fix is "Clean or Replace Spark Plug and Air Filter" (medium difficulty, ~30 minutes). Estimated DIY cost: $5-$15. 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 or Replace Spark Plug and Air Filter") is rated medium difficulty and takes about 30 minutes. Tools needed: 5/8" spark plug wrench, Flathead screwdriver, Feeler gauge, Wire brush.

DIY cost: $5-$15. Professional repair typically costs $100-$140. Many homeowners save money by trying the top-ranked community fix first.

The Craftsman S180 42cc Chainsaw has 7 other known error codes, including: MECH-CHAIN-BRAKE (Chain Brake Malfunction — Will Not Engage or Release), MECH-CHAIN-WONT-SPIN (Chain Does Not Rotate When Throttle Is Applied), MECH-DIES-UNDER-LOAD (Engine Dies or Bogs Down When Cutting), MECH-FUEL-LEAK (Fuel Leaking from Chainsaw — Fire Hazard), MECH-OILER (Chain Oiler Not Working — Bar and Chain Overheating), and 2 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 M110 140cc 21" Push Gas Lawn Mower, 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, and 3 more. The fix may vary by model, so check each model's specific page for tailored repair steps.