Important Information

Fuel recommendations

What kind of fuel should I use in my equipment?

We strongly recommend the use of NON-ethanol fuel for the following reasons:

  • 10% ethanol blend fuel only has a 30 day storage life.
  • Non-ethanol fuel has a 6 month storage life.
  • Ethanol has a lower BTU rating than pure gasoline.
  • Ethanol is corrosive to all metal parts, especially zinc. Many carburetors are made with zinc alloys.
  • Ethanol attracts moisture from the air around it and the combination of water and ethanol is far more corrosive than water alone.
  • Ethanol does something called phase separation in which the ethanol separates from the gasoline. In an engine that requires a gas/oil mixture, the oil stays with the gasoline and there is potential for straight ethanol with no oil to lubricate the engine.
  • Ethanol is more volatile than gasoline and in the warmer summer temperatures it can actually boil in the engine’s carburetor. When the engine is shut off to empty the grass catcher, the heat in the engine can flow back through the carburetor, along with the heat that transfers through the carburetor’s mount to the engine. Sometimes you can actually hear the sizzling sound of boiling fuel in the carburetor bowl. This is vapor lock and the engine will not start until the carburetor cools and stops vaporizing the fuel.


  • If you are experiencing hot restart problems try this. After you shut off your engine, pull the rope slowly until you feel resistence (compression). This closes the intake valve and stops the engines heat from flowing back through the throat of the carburetor. Some heat transfer will still occur but to a lesser degree.  


  • Regular grade 87 octane- Plus grade 89 octane- Premium grade 91 octane- Non-ethanol premium grade 92 octane or higher.
  • Oregon law has an exemption that allows for the sale of non-ethanol fuel in an octane of 92 or higher.
  • Most lawn mower engine manufacturers have a minimum 85 octane recommendation so our 87 octane regular is okay if you are using it up within the 30 day maximum storage life of the fuel. 
  • 2 cycle engines have a higher compression ratio which requires a higher 89 octane minimum. These engines are generally used on hand held equipment because of their lighter weight and ability to run at a much higher RPM.
  • Higher octane fuels will NOT cause damage to engines that don’t require them but using lower than the minimum can cause pre-ignition combustion known as detonation in which the compression of the hot air/fuel mixture causes combustion before the spark plug even sparks.
  • With all this in mind we feel it is better to use NON-ethanol 92 octane fuel for all of your outdoor power equipment.

How should I store my fuel?


  • Fuel storage life is affected by four main factors: age, temperature, exposure to sun light and exposure to oxygen.
  • Think of it like storing milk. You wouldn’t store your milk with the cap off the bottle, out of the refrigerator or use it long after the “best if used by” date.
  • With this in mind, you should never store your fuel outside in the sun with the vent open or the spout uncapped. This combination can cause even non-ethanol fuel to go bad in as little as 2 weeks.
  • Exposure to sun light in transparent or even colored plastic fuel tanks degrades fuel at an accelerated rate, in the same way that plastic (a petroleum based product) cracks and gets brittle or chalky when left in the sun for extended periods of time.
  • Ethanol contains oxygen and its addition to our fuel has an effect similar to storing your fuel in an unsealed container. Storage time is about 30 days.
  • Non-ethanol fuel has about a 6 month storage time.
  • Fuel storage additives or stabilizers will double storage time but only if it is kept in a sealed container and in a cool dark place.

I recently had a customer complain about his mini tiller giving him problems when it was only about 6 months old. The labels and stickers were faded from sun exposure and the fuel had that foul smell that old stale fuel has. When I suggested that he was leaving his machine outside in the sun, he protested and explained that he had never done that and that he kept it in his greenhouse. The sun and heat of the greenhouse had degraded his fuel and the pressure from the expansion of the heated fuel had actually popped the primer bulb on his carburetor. Surprisingly he had difficulty relating my recommendations of not storing his machine in the sun to his storing it in the greenhouse.


What is the correct gas/oil ratio for my equipment? (How much oil should I mix with my gas?)


  • This question must first be addressed with another question. What kind of 2 cycle oil are you using? There is a wide range of quality in 2 cycle engine oils. Liquid cooled 2 cycle engines have different service duty requirements from air cooled engines. You should never use 2 cycle outboard engine oils in an air cooled engine. Air cooled engines run hotter and at a higher RPM than outboard engines do. Just like automotive engine oils have an API service duty rating, 2 cycle engine oils also have a service duty rating system identified as ISO or JASO.
  • Currently the JASO rating for the best oils is FD. Service duty FE will exceed FD and so on.     
  • The richer oil ratios of yesteryear were predicated more on oil quality than engine design. Oils from the ‘50s through the ‘80s were basically non-detergent motor oil with differing amounts of solvents. Today’s 2 cycle oils actually have very little petroleum oil in them and are mostly chemical additives that lubricate and help transfer heat to keep the engines running within acceptable temperature ranges.
  • Bottom line is that even older engines can be run on ratios of up to 50:1 with today’s higher quality 2 cycle oils.   
  • There are different amounts of oil sold in small bottles that are pre-measured to mix with different amounts of gas, such as 1 gallon, 2 gallons or 2-1/2 gallons. A 50:1 ratio is 2.6 oz per each gallon of gasoline. These small bottles will hold more than they put in them so they can’t be used to measure from a larger bottle.
  • The best 2 cycle oils are the ones sold by equipment manufacturers and they can be found at the servicing dealer that sells that brand of equipment. The big box stores usually sell the lower priced, lower quality oils. You might save a little on these poor quality oils but you’ll pay for it 100 times over with the damage that they can cause.
  • DO NOT BUY oils that do not display the ISO or JASO ratings. This rating is the only way to know the quality of the oil and its ability to protect your engine.

Which oil should I use in my lawn mower engine?

The correct oil for a walk behind or riding lawn mower engine is determined by outside air temperatures and the engine manufacturer’s recommendations. This information is explained in your owner’s manual. If you don’t have or can’t find the manual, this information can be found at their website. Most manufacturers have down loads available if you have lost your manual.


What is the best way to store my equipment? (Should I drain the gas from my tank or leave it full?)

If you are using non-ethanol fuel, the fuel is fresh and you will not be storing it for more than 6 months, store it with a full tank and start your engine every couple of months. Let it run for about 10 minutes to reach full warm up. The fuel in your tank will not go stale as fast as the fuel in your carburetor, larger volumes of gas don’t get stale as fast as the smaller amount that is in your carburetor. Running the engine periodically refills the carburetor with fresher gas from the tank.

If it will be stored for more than 6 months, add a fuel stabilizer or storage additive when you purchase the fuel but still run it periodically as mentioned above.

Stand-by generators may be the least used but most relied on piece of equipment that you own. So always use non-ethanol fuel with a stabilizer in your generator and completely change out the fuel at least once a year. Don’t just add a little fresh fuel to the old stuff.
If you are using ethanol blend fuels, add a stabilizer when you purchase the fuel but you will have to completely change out the fuel every 90 days.

We don’t recommend trying to run the engine out of fuel because there will always be some fuel left in the tank, fuel lines and carburetor. There will be more air than fuel in these areas and what is left will leave a gumming residue. When it dries it will turn into a flaky scale that will brake loose and plug the metering jets that feed the engine with the correct amount of fuel.

I don’t have don’t have any inside storage. What is the best way to store it outside?

  • We sell covers that are form fitted for lawn tractors. The important thing is to cover the equipment without the cover laying on the ground. You need to let air flow under the cover so that the moisture that evaporates up from the ground doesn’t condense inside the cover and rain down on your equipment.
  • When you cover walk behind lawn mowers, roto-tillers, or any equipment with handles and control cables, be sure to cover the handles and cables as well as the engine. Rain will drain down into the cable conduit and stay there, rusting the cables and making them sticky or completely inoperable.
  • Whether you store your equipment inside or outside be sure to clean any grass from the top and underside of the mower deck. Grass holds moisture, moisture causes corrosion and corrosion shortens the life of your equipment.


What is the best way to clean my equipment?

  • The best and least damaging way to clean the top side of your mower is to blow it off with compressed air or a strong leaf blower if you don’t have an air compressor.
  • DO NOT use a pressure washer unless you know where NOT to clean. Pressure washers and even high pressure hose nozzles can force water into gearboxes, bearing seals and other places that the water will not be able to drain from. Remember it’s a lawn mower not a sidewalk. It has a lot of moving parts and water is not your friend when it comes to mechanical devices.
  • When it comes to cleaning, the most important and most neglected area on a lawn mower is the underside of the lawn mower deck. That’s where all the action is. Disconnect the spark plug wire before you do any work on your mower. Refer to your owner’s manual on the proper direction to tip your mower. Take a hose and simply rinse the fresh grass away right after you finish mowing.  You should give it a few minutes to cool off before rinsing but don’t wait too long. It only takes about 15 minutes for the grass to dry and get hard. After it dries you will have to scrape it off.
  • On most lawn mower engines it is best to tip the mower with the park plug pointing up. Don’t rotate the blade when the mower is tipped. After you’ve set the mower back on its wheels let it sit for about 10 to 15 minutes so that all the oil can drain back to the bottom of the engine.
  • We sell a product called Mo-Deck that comes in a spray can. You clean the deck first then spray it on and let it dry. It helps keep the grass from sticking to the deck and with a few applications during the season you will have a much easier time keeping it clean.

If you are having trouble with the grass catcher not filling up or grass getting stuck in the discharge chute. First make sure you have the correct blade on your mower (not one that just looks like it will fit). Second, make sure the underside of the deck is relatively clean. Now look at the inside of the grass catcher. Air needs to be able to flow freely through the fabric so that the grass can be blown into the grass bag. If there is a crust from grass juice plugging the open weave of the fabric it needs to be cleaned. You should be able to see light through the fabric. This is where you can use that pressure washer. If you don’t have one you can go to a coin-op car wash and clean it there. In either case wet the fabric first to soften the crust before you try to clean it. Be careful not to hold the wand to close or you might shred the fabric. After it is clean place the mower on a clean surface, start the mower and let the air flow of the mower blow it dry.

Where can I buy non-ethanol fuel?

Colvin Oil Company
20 South Stage Road
Medford, 97501

Hays Oil Company-Bi-Mor
1890 S Pacific Hwy
Medford, 97501

Pacific Pride
936 S. Central
Medford, 97501

Spirit Gas Station
1325 Court Street
Medford, 97504

2764 W Main St
Medford, OR 97501

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