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Troy-Bilt Lawn Mower Repair

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Many lawn mower problems are repaired with the help of the Troy-Bilt owner’s manual. Before you start, several steps ensure your safety. Make sure the lawn mower isn’t running and all parts, especially the blade, are stopped. Disconnect the spark plug wire and ground it against the engine so that it doesn’t start accidentally. Wear safety goggles protecting your eyes.

Seized Engine

An engine can seize when there’s no oil in the crankcase. If you can’t pull the start cord or the engine won’t turn over, this could be the problem. Check the oil. If the crankcase is empty, try spraying a penetrant into the cylinder through the spark plug hole and see if that loosens the seized piston. If this doesn’t work, the engine needs major repairs from a mechanic.

Engine Knocking

Your engine may knock if the piston contacts carbon deposits in the combustion chamber. Remove the cylinder head and clean the carbon. Repair the head gasket before reassembly. A loose flywheel also causes knocking. Make sure the flywheel key and nut are tightly secured. Fuel with an octane rating that’s too low for your engine also causes knocking. Check your owner’s manual for the correct octane level fuel for your Troy-Bilt lawn mower.

Fuel Line

A blocked fuel line keeps the engine from starting or causes it to run unpredictably. Inspect the fuel line and clean it if necessary. Clear the vent. When you’re done, drain the fuel tank and carburetor and fill the tank with clean fuel.


A small amount of blue smoke isn’t unusual to see in a two-stroke, Troy-Bilt lawn mower, but if you see a lot of blue smoke, adjust the oil-to-fuel mixture ratio because there is too much oil. You should never see blue smoke in the exhaust of a four-stroke engine. If you do, then oil has leaked into the combustion chamber or the carburetor, or you used a two-stroke engine fuel mixture. Use a brush or rag, and a liquid carburetor cleaner to thoroughly clean oil leaks. The presence of black smoke in the exhaust indicates that the air-fuel mixture is too rich. Inspect the choke. If it’s open all the way, then the carburetor is the problem.

Carburetor and Sparkplugs

Carburetors and sparkplugs cause several problems. If your Troy-Bilt lawn mower idles poorly, the sparkplug might be clogged with oil, gas and combustion residue, or the sparkplug may be faulty or need the gap reset. Check the gap with a sparkplug gauge and reset it to .030 inch if necessary. Clean the sparkplug with a wire brush. Reset the gap if your lawn mower hesitates at high speed.

Cutting Blade

A loose or unbalanced cutting blade can cause your Troy-Bilt lawn mower to vibrate. Tightening the blade and adapter and making sure the blade is balanced corrects this problem. If the blade is bent, it needs replacing. If your mower won’t mulch or produces an uneven cut, the blade is dull and needs sharpening or replacing. Cleaning grass and other debris off the undercarriage also helps.

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