The 3 Reasons Why Your Tiller Engine Is Running Poorly

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It seems to arrive faster every year, but it’s that time again for the green thumbers among us to prepare for a successful planting season by tilling the earth. If you’ve been using the same gas-powered tiller to do this job as you have in past years, you may be frustrated to discover the tiller engine is running rather poorly this time around. Is it time to get a new gas-powered tiller? Not necessarily. Repair Clinic recommends doing a little troubleshooting by considering the three most likely reasons why the tiller engine is running poorly. With a replacement part or two and a little help from your repair partner, you may be able to get that engine running like new.

Know what kind of fuel powers the tiller’s engine

Keeping your tiller’s engine in good condition is largely dependent on what you put into it, so it’s a good idea to know what kind of fuel powers the tiller’s engine. Home-use gasoline-powered tillers will either have a four-cycle engine or a two-cycle engine. While a four-cycle engine normally relies on SAE 30-weight oil poured into its own sump for proper lubrication, a two-cycle engine requires the oil to be mixed with the gas in the fuel tank for the engine to operate properly. Operators should be aware that attempting to run a two-cycle engine without a suitable gas and oil mixture will cause the engine to seize due to insufficient lubrication. If you find the idea of getting an accurate gas/oil balance daunting, there are pre-mixed fuel and oil products like TRUFUEL 50:1 Mix on the market that make this easy; just pour the pre-mixed formula into the tiller’s gas tank and you should be all set.

Never use gasoline with more than 10% ethanol

As for the gasoline you’re using, you should never fill the tiller’s tank with gas that contains more than 10% ethanol. Gasoline with higher levels of ethanol can be corrosive and attract moisture which can damage the fuel system. It’s also a good idea to add a fuel stabilizer to either the gas container you use to fill the tiller’s tank or directly to the tank itself. This will help keep the fuel fresh for a longer period of time and delay the oxidation and evaporation which can cause gasoline to become stale.

The three likely causes of a tiller engine running poorly

So, you’re pretty confident you’re putting fresh fuel or the right fuel mixture in the gas tank. What else could be causing the tiller engine to run poorly? Here are the three most likely causes:

  1. Restricted carburetor – Despite putting some fresh fuel into the tank, it’s possible that old fuel left in the tank in years past has caused a gummy residue to build up inside the carburetor. This can create a restriction that will prevent the proper ratio of fuel and air from entering the cylinder resulting in the engine running poorly. As noted earlier, if your tiller engine is two-cycle, you can use a premixed fuel and oil product for better stability. You can try cleaning the carburetor ports with a dedicated carburetor cleaner, or WD-40, to clear out the restriction, but if the clog is particularly bad, you may need to purchase a new carburetor.
  2. Defective spark plug  –  Due to carbon build-up or a weakened electrode, a spark plug will degrade over time and may only intermittently ignite the compressed fuel and air inside the engine’s combustion chamber. This can cause the tiller engine to run poorly. You can use an ignition tester to help determine the strength of the spark plug, but it’s probably easier to simply replace it with a new one, something we recommend doing annually.
  3. Clogged fuel filter – That gummy residue that can clog a carburetor can do the same to the fuel filter. Cleaning out a fuel filter is rarely successful and will probably just damage the component. It is far better to simply replace the old, clogged filter with a new one to resolve the issue. You can prevent problems with the engine running poorly by replacing the filter as part of your annual tiller engine tune-up.
Tiller Engine Runs Poorly? Top 3 Reasons – Tiller Troubleshooting

Fix your tiller engine with genuine OEM parts from Repair Clinic

Whether you’re replacing a tiller engine carburetor, fuel filter, spark plug, or any other component, Repair Clinic recommends using only genuine OEM (original equipment manufacturer) parts. An original manufacturer part is specifically designed to work with your particular engine model, so you can extend the life of the engine and get a better performance out of it by using an OEM part instead of a generic version which may not be as compatible. Repair Clinic stocks original equipment manufacturer parts from such industry leaders as Briggs & Stratton, Craftsman, Echo, Homelite, Honda, Husqvarna, Lawn Boy, MTD, Mantis, Poulan Pro, Ryobi, Toro, and Troy-bilt. To find the right engine component that matches your tiller, enter the full model number of the equipment or the engine itself into the Repair Clinic website search bar. The resulting list will be all the parts compatible with your tiller. From there, you can refine the list by using the “Part Category” navigation filter (example: “Filter”) followed by the “Part Title” filter (example: “Fuel Filter”) to identify the specific part or parts you’re looking for.

Repair Clinic is your one-stop repair resource

In addition to carrying millions of OEM parts that ship quickly, Repair Clinic is your one-stop repair resource for learning how to fix all of your outdoor power equipment, major home appliances, and heating and cooling systems. Visit the Repair Clinic website’s “Videos & Articles” section for free “how-to” content including thousands of procedural videos like this one showing how to replace a transmission drive shaft on a model 7262 Mantis tiller. You’ll also find a treasure trove of diagrams, equipment schematics, and articles (such as this one explaining proper tiller maintenance). For do-it-yourselfers and professionals alike, Repair Clinic makes fixing things easy.

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