Small Engine Repair: When To Rebuild, When To Replace, What It Costs

Your small engine is dead. Blown piston rings, scored cylinder, burned valves, seized bearing. Decide: rebuild or replace? Here's the cost breakdown.

Most Common Rebuild Cases

Blown Piston Rings ($220-330): Compression leaks. Engine loses power. Burns oil. Smokes. New engine $600-1200. Rebuilding saves $300-900.

Scored Cylinder ($280-470): Piston rode metal on metal. Bore 0.010" oversize, install oversized piston and rings. Prevents $600+ new engine.

Burned Valves ($170-320): Metal erodes. Valve doesn't seal. Remove, grind seat smooth, install new valve.

Cracked Piston ($360-550): Breaks into pieces. Jams between piston and cylinder. Remove, clean fragments, install new piston.

Seized Bearing ($470-700): Bearing runs dry, seizes on crankshaft. Engine locks. Remove connecting rod, install new bearing.

When Not To Rebuild

Bent crankshaft: impossible to rebuild. Replace engine. Cracked block: replace engine. Multiple simultaneous failures: complete teardown $800-1200. New engine $600-1200 becomes better choice.

Real Case

Contractor brought 6.5 HP Honda GX engine. Losing power. Burning smoke. Diagnostic: blown piston rings. We rebuilt: new rings, gaskets, oil seal, honed cylinder, tested. Compression back to factory spec. Cost: $280. He saved $600 by not replacing.

Timeline

Simple repairs: 1-2 hours, $35-85. Ring replacement: 4-6 hours, $220-330. Valve work: 3-5 hours, $170-320. Complete rebuild: 12-20 hours, $800-1500.

Most within 3 days. SBS customers get priority. Stop-the-shop service available same day for extra charge.

Call 301-519-9274.

About the Author

Henry Bockman rebuilt hundreds of small engines. He knows whether yours is worth rebuilding or should be replaced.