Tiller: Engine runs rough or misfires

If your tiller engine isn't running smoothly, cleaning or replacing the carburetor, tuning up the engine or replacing bad gas may fix the problem.

If you left gas in the tank during the winter without adding fuel stabilizer, drain the tank and fill it with fresh gas. Add fuel stabilizer to gas to keep it fresh during the off-season.

Stale fuel can clog the carburetor, so clean and rebuild the carburetor if the tiller continues to run rough or misfire after replacing the gas in the fuel tank. Replace the carburetor if it's too clogged to clean.

Tune up the tiller engine by replacing the spark plug and oil. A dirty spark plug won't ignite the fuel properly. Old oil won't lubricate engine parts well so the engine idles roughly because the piston or pistons won't move smoothly through the cylinder.

tiller

These repairs may help solve your tiller problem

Clean and rebuild the tiller carburetor

Clean and rebuild the tiller carburetor

Rebuild kits are available for most carburetors. The kit contains the essential components such as jets, pins, seals and gaskets to overhaul the carburetor. You can sometimes fix a fuel supply problem by disassembling and cleaning a carburetor. Use the rebuild kit to rebuild the carburetor after cleaning it.

Replace the tiller carburetor

Replace the tiller carburetor

Over time, varnish from stale gasoline builds up in the carburetor, decreasing the amount of air/fuel mixture reaching the engine. Replace the carburetor if it's severely clogged with varnish or if the orifices are clogged with debris and can't be cleared using carburetor cleaner and compressed air.

Tune up the tiller engine

Tune up the tiller engine

A tune-up restores the tiller engine to its peak operating condition. A tune-up includes changing the oil, cleaning the engine, replacing the air filter, checking the ignition system, inspecting the carburetor, adjusting the throttle and choke controls, and adjusting and lubricating all moving parts.

Symptoms common to all tillers

Choose a symptom to see related tiller repairs.

Main causes: carburetor failure, bad gasoline, dirty spark plug, broken recoil starter
Main causes: clutch cable problems, faulty transmission
Main causes: dirty carburetor, engine needs tune up, stale gas
Main causes: damaged tines, broken clevis pins, worn drive belt, faulty transmission, clutch cable problems, improper depth-stake setting
Main causes: leaky engine head gasket, damaged sump gasket, damaged oil drain plug seal, loose or cracked fuel line, leaky carburetor seal
Main causes: broken shaft clevis pins, transmission failure
Main causes: worn or broken drive belts, bad transmission, clutch cable problems
Repair guides common to all tillers

These step-by-step repair guides will help you safely fix what’s broken on your tiller.

May 1, 2013
By Lyle Weischwill
How to replace a tiller recoil starter

The recoil starter spins the engine when you pull the starter rope, and the rope retracts when released. If the recoil starter assembly is broken, follow the steps in this repair guide to replace it.

Repair difficulty
Time required
 15 minutes or less
Articles and videos common to all tillers

Use the advice and tips in these articles and videos to get the most out of your tiller.

November 1, 2016
A guide to garden tillers
By Sears PartsDirect staff

Rear tine tiller or front tine tiller, what to know to help in choosing the correct one for your needs.

November 1, 2015
Tiller common questions
By Sears PartsDirect staff

These frequently asked questions might help you figure out what's wrong with your garden tiller.