J and J Small Engine Blog

As 2011 draws to a close many of our customers will be storing their STIHL products for the season. Fuel-related problems are among most common issues that STIHL customers have.

Now Let's Talk About Gasoline

The gasoline we buy at the pump is not the same as what we bought 10 years ago. Gasoline is a complex chemical soup that must meet standards set by the EPA regarding the pollution created when the fuel is used in an internal combustion engine. Nearly all the fuel sold today has at least 10% ethanol added. The primary use of gasoline today is for licensed vehicles used on public roads, like cars and trucks. Today the majority of these vehicles are fuel injected with a computerized engine management system that tunes and adjusts the engine to the fuel as the vehicle is being operated. The fuel companies blend this fuel to meet EPA standards for these vehicles.

Today's gasoline is even blended differently by region and at different times of the year to help with cold and hot starting in your car or truck. It is expected that gasoline delivered to a gas station will be sold and used within two or three weeks.

Most small engines manufactured today, for lawn and garden applications as well as small outboards and recreational vehicles, still use carburetors to mix the fuel with the air for the engine to run. The challenge for small engine manufacturers has been to build their products to operate properly on gasoline blends that keep changing. This has lead to such things as materials compatibility. Here is an example: take an engine that is a few years old and ran fine last season, but now will not start. When the unit is evaluated by a service technician at the dealership, they may find that the fuel line was found to be hard and brittle and had crumbled away, or it may have become soft and spongy and simply collapsed so no fuel can flow through it.

In some cases the carburetor itself may be damaged by the fuel, clogging jets or damaging rubber or polymer components that the fuel comes into contact with. They may swell or shrink, causing problems that prevent the machine from running correctly. It is easy to blame some of these problems on the ethanol that is mandated by the EPA to be added to most fuels, but there may be other additives in the fuel that could be a cause of these problems as well, especially in older machines.

Available Options

So what should you do to make sure your small engine will start when you want it to? There are some options available. They may require spending more money on fuel, or more time in preparing the machine for off-season storage, but the cost of not doing these things will be down time and a repair bill to correct the problems.

STIHL continues to make changes to the polymers and the carburetors used on current products to help prevent this sort of thing from happening. We do have some recommendations to help prevent starting problems for anyone with a small air cooled engine equipped with a carburetor, regardless of how old it is.

The most important thing you can do is buy name brand (89 or higher) octane fuel. The reason is that name brand fuel (Shell, EXXON, BP, CITGO, etc.) is blended more consistently and should be fresher and of a higher quality than fuel bought at a retailer with no brand on the pump.

Only buy enough fuel to last you a month at a time. The shelf life of today's gasoline is not as long as it was in years past. Fuel does "go bad" over time and will change color and eventually have a sour odor. This can happen much faster if the fuel container is open to the atmosphere, as in some older gas cans that do not seal out the air.

Some older gas cans have a little plastic vent that you would open to allow the fuel to pour out, and often it will break off and the oxygen in the air can get inside the gas can and start a process called "oxidation" that will rapidly degrade the fuel. Always use a clean fuel container and consider buying a new one that has a positive sealing dispensing cap and an automatic vent.

In high humidity areas, the ethanol additive in the gasoline will rapidly absorb moisture from the air and "phase separation" can occur. This will cause the water and ethanol to settle at the bottom of the container. When the can is tipped up to fill the tank, the water and ethanol will flow into your machine's fuel tank possibly causing a non-start condition. In a worst case scenario, this can actually ruin the carburetor or even cause internal damage to the engine.

Do not use a "winter"-blended gasoline you bought in January in June, as it may cause lean running, vapor lock, hard-starting and could also lead to internal engine damage.

Another suggestion that you might consider is to add a fuel stabilizer, such as STABIL. Be sure whatever brand you buy does not have any alcohol in it. A fuel stabilizer will not fix old gasoline but it does help lock down the chemistry of fresh gasoline so if it does sit in your gas can for a month or two, it should still burn properly when you use it. But remember that adding a fuel stabilizer does not make your gasoline last forever, just longer than it would without a stabilizer added. Some two-cycle engine oils have stabilizers as part of their chemistry, which makes it convenient to have a stabilizer in the mix.

Use a dedicated two-cycle fuel can. If you have a two-stroke engine such as a chain saw, leaf blower, or trimmer, use a fuel can just for two-cycle mix, and label it clearly. We suggest using the best quality oil from the manufacturer of your particular machine, and put the oil in the can before you add the gasoline so that it mixes better and there is no chance of forgetting to add it later.

Another option is to buy pre-packaged fuel for your two-stroke equipment. STIHL markets MotoMix® which is a 92 octane fuel with synthetic oil already added at a 50:1 ratio, and there is no alcohol of any kind present. Additionally this fuel will remain stable and useable for up to two years after the seal on the container is broken as long as the cap remains tightly sealed. While this option is more expensive up front, the payoff will be no downtime or repair bills down the road. This may be a good idea for someone that uses their equipment only occasionally, like a homeowner, fire department, rescue squad or farmer.

Prepare it for long term storage. Finally, no matter what gasoline you use, the most important thing to do when a machine is going to sit for any length of time, say over three or four weeks, is to actually run it out of fuel. Carefully drain the fuel out of the tank if it is not near empty, and save that fuel or dispose of it properly. Now start the engine and let it run at idle until the engine runs out of gas and stops. Don't rev the machine, just let it idle. This will do more than anything else to help mitigate starting problems the next time the machine is put into service. There will always be a little gasoline left in the carburetor, so this is why it would be best if the gasoline had some stabilizer in it, or for a two-stroke, a product like MotoMix®.

Remember, selection of fuel and proper mixing is your responsibility. Use a name-branded fuel and two-cycle mix, and follow the information above. Your machine should be ready when you are. If you have questions, contact us by calling 774-987-9399 to speak with our experienced technicians.

On Black Friday, shop locally for your power tools and stocking stuffers. Why should you shop local? Shopping locally promotes our communities small businesses and helps keep dollars in our local economy. Locally owned businesses keep more revenue in the local economy than big box stores do. Supporting local businesses also supports local jobs and keeps business in the community.

But if you have an American Express Card, you get a credit for shopping locally. This Saturday  is Small Business Saturday. Card members will receive a $25 statement credit when they register and spend $25 or more at small businesses that accept American Express. J&J Small Engine Clinic is just that kind of store.

Come on in for stocking stuffers for the lovers of power tools in your life. Stocking stuffers like engine oil, gift cards, ethanol free gasoline, or anything else a small engine DIY needs make a special holiday gift.
 
Businesses like J&J Small Engine Clinic are run by entrepreneurs and are essential to our communities and local economies. Contact J&J Small Engine Clinic.

For more information on American Express’ small business Saturday, please visit http://smallbusinesssaturday.com/

Performing power tool maintenance prior to storage is always your best option. Replace your Air Filter and clean any debris that have collected in the air filter housing. Never used and solvents or compressed air. Compressed air will create tiny holes in the air filter allowing debris into the carburetor.  In North Attleboro, power tools like snow blowers, rototiller and lawn mowers are used seasonally so they need to be stored correctly too.

Change your Oil and  oil filter (if applicable). Oil is as important as the Air filter and should always be kept clean & Full. Drain oil (replace oil filter if applicable) , refill with the proper oil viscosity (10w-30,SAE 30, 5w-30) Refer to your owners Manual for this information. Never Leave The Engine Drained of Oil.              

Make sure mower blades are sharp and that the chains of a chain saw are not worn out. Have your blade(s) sharpen or replaced.

Every season the spark plugs should be replaced.

Replace the starter rope if it is frayed.

Store your small-engine equipment and power tools properly at the end of the season. Change the oil, they should be stored with clean oil. But do not let power tools sit with gasoline in them. Gasoline goes bad very quickly. Gas Additives that contain Stabilizers with help for long term storage.The best way to be worry free of Gas going bad is to use an Ethanol Free Gasoline.  J&J Small Engine Clinic, Inc, Is one of the Few Shops to sell this gasoline. Ethanol free gasoline will not go bad for at least two years, most gasoline purchase for your vehicle will start to go bad in 30 days.

Contact J & J Small Engine Clinic on any power tool maintenance service needs.

Proper small engine maintenance of your equipment with gas engines should begin with you checking the oil every time before you start the engine.
 
Many people wonder how often they should change the oil in a small engine. You should definitely see what it says in the owner’s manual. However a good rule of thumb is to change it every 20-30 hours of use.

The next question we often hear is: what kind of oil should I use in my small engine? Well, again you should refer to the owner’s manual. The manufacturer will recommend a certain rating. Brand doesn’t necessarily matter as long as it is a recognizable one.

Some manufacturers will recommend a specific viscosity oil, while others will recommend that you use a multi-viscosity type. A generic approach would be to use a 30 WT for warmer seasons and for winter or cold temperature operation, 10W30 should be fine.

Contact J & J Small Engine Clinic to schedule your small engine service.
 

Many small engines are in good repair, but they start smoking when you start them up. In many cases, you may be able to fix this on your own. Here are some quick tips on what to look for to try to solve your smoking small engine.

1. You may have a dirty or plugged air filter. Replace or clean it.
2. Worn Damaged Rings. Rings and cylinder may be worn past their tolerances due to age and lack of maintenance. In this case it, bring the engine in to be evaluated for repair options.
3. Loss of crankcase vacuum. Make sure the dipstick or fill plug is secured tightly. You may also have bad O-rings, gaskets and washers. 
4. Scored cylinder. This is caused by ingesting dirt. Either a very dirty air filter or a missing air filter will cause this.
5. You may be using the wrong grade/viscosity of oil. It is very important to use the proper viscosity recommended by the manufacture. It is also important to use oil designed for Air-Cooled Engines, most oils in stores are designed for automobiles with water cooled engines.
6. Some engine failures are due to Gasoline. Either  gas sitting stagnant and clogging the carburetor, or the Ethanol in the gasoline has caused some kind of failure to the components.  The float no longer shuts off the gas and causes it to leak into the oil. This will also cause the engine to smoke and will required repair. 
7. Leaking head gaskets. A head gasket typically leaks due to the engine overheating . Nesting or grass build up in your engines cooling fins prevent the proper amount of air circulation to cool itself and the engine overheats, warping the cylinder head causing the gasket to no longer seal properly. Low oil, Running the engine for a long period of time with low oil will also cause the engine to overheat, when the oil is then filled to the proper level it leaks by the head gasket. This situation would have to be diagnosed and repaired.
8. The choke is still on. Open the choke as soon as the engine fires and continues to run without stoppping.
9. There may be too much oil in the engine. Correct the amount of oil in the crankcase. Fill it only to the "Full" mark.