Wednesday, October 22, 2014

Workshop Wednesday-Small Engine Fuel

 This time of year our inbound repair shelf at the shop is full of leaf blowers and chain saws that ran fine last year but now won't start. Soon it will be snow blowers. As a small engine mechanic I see more fuel related problems than anything else. There are two reasons for this. The first is ethanol. Its just not a good fuel for small engines. Most equipment more than just a few years old has rubber components that won't stand up to ethanol. Typically I see more than one piece of equipment a day that has a broken fuel line in the tank with the filter just laying there unconnected to anything. It ran a while like this and now the carb has crap in it. There is also the problem of phase separation.  Google it, but basically it comes down to the fact that ethanol absorbs a point. Then it separates and what you are left with is a layer of water on the bottom of your tank or gas can. When you tip and pour a gas can you get the stuff from the bottom first and that could be a large dose of water. Not good. I'm not going to get into the politics of ethanol but right now its just not a good fuel for small engines.
 The second fuel related problem I see is "stale gas". The equipment was used and ran fine. Then it sat in the shed till the next year when it was needed. Even if it was ethanol free fuel, it will evaporate and leave behind a big mess most people call "varnish". This is the stuff that plugs up tiny ports and jets in carbs.

 A few years back we started selling canned fuel. This is one example. There were a lot of claims about this stuff. We were told this fuel would stay fresh in an engine for two years. Ideal if you are a casual user of certain equipment. For example you have a hedge trimmer that only gets used a few times a year. A quart of fuel may be the total volume for the whole season. This stuff would be perfect for that if it worked up to its claims.
 I'm a "show me" kind of guy. I decided I needed to conduct my own experiment.

 About 27 months ago I salvaged an engine from a piece of equipment headed for the dumpster. I drained the gas and added SEF (small engine fuel). I ran the engine till I knew all the old gasoline was worked out of the carb and it was running on just SEF. Then I shut it off. I was certain the carb now only had SEF in it. I attached the tag in the pic and dated it 7/17/12. I then pushed the engine in the corner and pretty much forgot about it. Oh sure I'd see it every so often and be tempted to try to start it but I managed to hold off.
 Yesterday I noticed the engine and decided it was time to test out the claims. It was over the two year mark so figured why not. When I opened the cap on the fuel tank I noticed the tank appeared dry. I think a lot of the fuel evaporated and couldn't help but wonder if it "varnished" in the carb. I added some more SEF, turned the ignition switch on, moved the choke lever and gave it a pull. Sure enough it fired right up! I was truly impressed that this old piece of junk started on first pull. I let it run a while and it never missed a beat. I'm sold. I'm also relieved that all that canned fuel we sold was actually doing what we claimed it would do.
 Canned fuel isn't cheap but neither are repair costs. No snake oil here, this stuff works. Husqvarna offers to double the two year warranty on certain small equipment if three cans of their 50:1 mixed fuel is purchased at the time of the new equipment purchase. That says a lot.
 So if you've ever considered using this type of fuel but weren't sure if it was any good, go ahead. It has the Greasy Shop Rag stamp of approval.

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