Craftsman Craftsman B210 27cc 2-Cycle Gas Leaf Blower (210 MPH) MECH-RUNS-ROUGH Error Fix: Engine Surges or Runs Erratically

Error code MECH-RUNS-ROUGH on the Craftsman Craftsman B210 27cc 2-Cycle Gas Leaf Blower (210 MPH) means: Engine Surges or Runs Erratically. The blower engine speed cycles up and down (surging) or runs inconsistently. This is essentially the same diagnosis as for other 2-cycle equipment — most commonly caused by: (1) Dirty carburetor — old fuel varnish partially blocks jets, causing inconsistent fuel delivery. Clean the carburetor thoroughly. (2) Clogged gas cap vent — creates a vacuum in the tank. Loosen the cap while running — if surging stops, the vent is blocked. Replace the cap. (3) Fuel line deterioration — cracked lines allow air into the fuel system. Replace. (4) Carburetor adjustment — the Low-speed (L) screw may need adjustment for stable idle. (5) Air leak at carburetor gaskets — loose carburetor mounting or worn gaskets allow unmetered air to enter, leaning the mixture intermittently. Retighten carburetor bolts and replace gaskets if worn.

The most successful fix is "Replace Fuel Lines and Adjust Carburetor" (hard difficulty, ~45 minutes). Estimated DIY cost: $15-$30. HomeMD has 2 community-ranked fixes for this error.

This error is rated low severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Yes — the top-ranked community fix ("Replace Fuel Lines and Adjust Carburetor") is rated hard difficulty and takes about 45 minutes. Tools needed: Flathead screwdriver, Phillips screwdriver, Fuel line pliers, Carburetor adjustment tool.

DIY cost: $15-$30. Professional repair typically costs $150-$250. Many homeowners save money by trying the top-ranked community fix first.

The Craftsman Craftsman B210 27cc 2-Cycle Gas Leaf Blower (210 MPH) has 5 other known error codes, including: MECH-FUEL-LEAK (Fuel Leaking from Blower — Fire Hazard), MECH-NO-POWER (Loss of Blowing Power — Weak Airflow), MECH-OVERHEATING (Engine Overheating During Extended Use), MECH-PULL-CORD (Pull Cord Breaks or Will Not Retract), MECH-WONT-START (Blower Engine Will Not Start).

Error code MECH-RUNS-ROUGH also appears on 6 other Craftsman models: 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, T210 46" Turn Tight, Z560 54 in 24 HP V-Twin Zero-Turn Riding Mower. The fix may vary by model, so check each model's specific page for tailored repair steps.