GAS,CARBS, AIRPLANE FUEL

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dls

ArboristSite Operative
Joined
Jan 15, 2009
Messages
122
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Location
Jackson, Miisouri
Crappy gas last few years has ruined a lot of saws. Everyone knows it. I found 1 station in the county that sells gas that does not have alcohol in it but the delivery driver tells me if the station orders 7,000 gallons and the regular tank won't hold it all, they just drop the hose in the premium tank. Sweet. I've probably gone through 30 pistons and cylinders in the last 1/2 dozen years. Before that I only had to replace 1 in 30 years. Part I blame on the carbs too. A guy at the dealer told me yesterday to put Walbro carbs on my 044's to have fewer problems. I looked today and all 5 have Zama (I always thought they were crap and they keep changing the part numbers) and all my spare new ones in boxes are Zama. Any opinion? Are Zama and Walbros knock offs of each other with interechangable parts as different venders for same stihl models? He also told me he knows a guy that uses aviation fuel in his saw. Any thoughts or experience on that? Thanks guys.
 
I could write for hours about this. Ethanol Alcohol is hygroscopic. It pulls water out of the air. High moisture in the crankcase and rings, and bearings, causes trouble. Stops up the carburetor. Makes it run lean. That means hot.
I like Star Tron, (gas additive) It makes em run. But, ethanol is just plain bad.
N
 
I use nothing but 87 pump gas with ethanol (its more than an hour to the nearest e-free at a gas station) Between blowers/trimmers/saws i run hundreds of tanks of fuel through stuff every year. Ive never had an issue other than carb kits and fuel lines. My backpack blower alone has hundreds of tanks of fuel over 5 or 6 years, original carb kit and fuel line. If ur the type that lets ur stuff sit outside, and sit for months at a time without use then yeah, youll have issues.
 
I use nothing but 87 pump gas with ethanol (its more than an hour to the nearest e-free at a gas station) Between blowers/trimmers/saws i run hundreds of tanks of fuel through stuff every year. Ive never had an issue other than carb kits and fuel lines. My backpack blower alone has hundreds of tanks of fuel over 5 or 6 years, original carb kit and fuel line. If ur the type that lets ur stuff sit outside, and sit for months at a time without use then yeah, youll have issues.
+1 me too!
 
I use nothing but 87 pump gas with ethanol (its more than an hour to the nearest e-free at a gas station) Between blowers/trimmers/saws i run hundreds of tanks of fuel through stuff every year. Ive never had an issue other than carb kits and fuel lines. My backpack blower alone has hundreds of tanks of fuel over 5 or 6 years, original carb kit and fuel line. If ur the type that lets ur stuff sit outside, and sit for months at a time without use then yeah, youll have issues.

I haven't even had any carb or fuel line problems from E10 gas. Not even in my 21 year old Honda generator that runs 1-2 weeks a year. I haven't burnt up or seized a piston in 30 years (and those were due to my mistakes not the fuel). The few carb rebuilds I've done have been due to letting them sit with gas in them for a year or more (I try to avoid that but forgot).

The evils of E10 are way overblown. If E0 was available nearby and didn't cost much more than E10 I'd use it, but that's not the case where I am.

E10 does make engines run a little leaner than E0 (about 4% change to the effective air:fuel ratio). But if you're on this site you know how to tune carbs so that should not be a problem.

I used 87 octane in saws for a long time but discovered that the manuals call for 89, so I use that or premium now. You often don't hear two stroke detonation. I have not noticed a difference in how they run.
 
I use nothing but 87 pump gas with ethanol (its more than an hour to the nearest e-free at a gas station) Between blowers/trimmers/saws i run hundreds of tanks of fuel through stuff every year. Ive never had an issue other than carb kits and fuel lines. My backpack blower alone has hundreds of tanks of fuel over 5 or 6 years, original carb kit and fuel line. If ur the type that lets ur stuff sit outside, and sit for months at a time without use then yeah, youll have issues.

Nothing sits and I am fortunate enough that when there was money enough to do it, I built a heated building. Tools and parts don't sweat and rust with weather changes because it is climate controlled. I don't see how you do it. Motor cycle people, chainsaw people, lawn boy owners all complain about ethanol ruining pistons and cylinders. I only use Stihl synthetic additive and mix it rich and still buy a million pistons and cylinders.
 
I run Home Depot's PowerCraft brand of 40:1 canned fuel in all my two strokes that do not get used regularly and in the small saws. Otherwise I run Chevron 91 octane Supreme in everything else at 40:1. I have not had any problems in years. The only thing I do differently is before I fill my cans I dump out the left over gas no matter how little there is. There is usually some sawdust or other crud in the bottom of my cans. I don't store pump gas for me two strokes either.
 
I've been running AV 100LL for years with zero issues. It helps to have
a local small airport 2 miles from me.

Thanks. That is an answer I needed. Non ethanol fuel is near impossible to get here, especially when the tanker driver says the use what is left to top off the premium tank adding ethanol to it too. I will call the airport tomorrow and see how to get some.
 
I looked into this option as well, I was told airplane fuel is leaded and around 100 octane. I found e-free gas at a back woods dirtbike shop. If airplane fuel don't work out for ya, try a dirtbike shop. Dirt bike shop owner asked me like 3 times what I was using it for, I think he was worried I was going to use it for "On road use".
 
I know different states have different requirements in fuel. Ten to fifteen percent alcohol does not matter in petroleum based fuel. If you are using that then your problem lies elsewhere. If you are using fuel with more than twenty percent alcohol then you could have some kind of argument, but I doubt it. I realize that most of you live in a low altitude environment. So in other words your adjustments need to be more precise than those of us who live in higher altitudes. When using alcohol your day to day use can change even from morning to night. I built race engine for a living a number of years ago running all most one hundred percent alcohol. Other than some of the obvious like hoses the factors are the same. If you let your saw or fuel sit around for a month and do not adjust your carburetor or be prepared to adjust your carburetor every single time you use your saw there is your problem. Ave gas is not the answer for most in that it is loaded with lead and is engineered for a completely different task. Aircraft motors for most part are constant RPM motors that are four stroke motors with often aspiration assist. I have used standard Costco regular fuel ever since Costco started conducting business with out one single failure. When I start a saw it is usually to start on a twenty cord project or more. There was a time when I went out of my way to buy a small drum of premium gasoline and a barrel of Trick brand race fuel for premix for my dirt bikes. On occasion I even used Costco premium in those motors with out a problem. Thanks
 
Sigh. The ETOH boogie man……again. Been running 10% ETOH forever at 50:1 with good quality oil or synthetic. Never had a problem I can contribute to ETOH fuel. Used to run stuff dry, date fuel and dump it into the truck. Now I don’t bother to even drain it. Left a trimmer one winter with a full tank of fuel. Drained it in the spring expecting to see water, separation, orange juice jones etc. Fuel I drained out looked and smelled better than the fresh mix I put back into the trimmer. I said to my self “self you got rocks in your head doin’ this”. Have not drained a machine since. Recently took an ms361 off the shelf that has sat for 4-5 years with a tank of ETOH fuel. Started and ran just fine. Popped it back on the shelf for another couple of years testing to see if I can get some ETOH fuel problems.
 
Try a motorcycle shop/dealer. Many have race fuels like VP and Sunoco that have specialty fuels with and without ethanol. Or small airports have AV gas that is ethanol free.
 
I haven't even had any carb or fuel line problems from E10 gas. Not even in my 21 year old Honda generator that runs 1-2 weeks a year.
The evils of E10 are way overblown. If E0 was available nearby and didn't cost much more than E10 I'd use it, but that's not the case where I am.
I used 87 octane in saws for a long time but discovered that the manuals call for 89, so I use that or premium now. You often don't hear two stroke detonation. I have not noticed a difference in how they run.

I have no problems in Honda engines on the air compressor or pressure washers except fuel goes bad in a month unless I put Stabil in it. The piston and jug issues have been exclusive to Stihl, the only 2 cycles I have but I see ads all the time on the 4 wheelers, mopeds, dirt bikes, boat motors and used saws for sale with cylinder and carb problems so it is not exclusive to me. I always buy premium and for the saws instead of 2 gallons gas to 1 bottle of Stihl synthetic oil, 1 3/4 gallons.
 
Crappy gas last few years has ruined a lot of saws. Everyone knows it. I found 1 station in the county that sells gas that does not have alcohol in it but the delivery driver tells me if the station orders 7,000 gallons and the regular tank won't hold it all, they just drop the hose in the premium tank. Sweet. I've probably gone through 30 pistons and cylinders in the last 1/2 dozen years. Before that I only had to replace 1 in 30 years. Part I blame on the carbs too. A guy at the dealer told me yesterday to put Walbro carbs on my 044's to have fewer problems. I looked today and all 5 have Zama (I always thought they were crap and they keep changing the part numbers) and all my spare new ones in boxes are Zama. Any opinion? Are Zama and Walbros knock offs of each other with interechangable parts as different venders for same stihl models? He also told me he knows a guy that uses aviation fuel in his saw. Any thoughts or experience on that? Thanks guys.
The main difference with the av gas is the lead. If you like inhaling a bunch of toxic crap, and you will because saws don’t burn all that cleanly, that’s what you are looking at. I always go for non ethanol 87 or higher. Most of the newer oil blends have stabilizer, and stuff to help ethanol burn. The only problem is ethanol doesn’t lubricate, so putting it in a two stroke is not a good idea. I run it in my zero turn all the time, when it’s getting a lot of use, but never during the end of the season when it needs to be stored. Most newer 4 strokes are fine to run it, because they changed up their fuel system.
 
Hey guys, I’m not a chainsaw wizard or anything, but I have worked on piston aircraft for a long time. I can get 100LL for free and I would not run it in any small/large engine I own. I ruined several VW engines with it (when they were air cooled) thinking it was the answer to jack up the octane. They didn’t ping for sure but the extra heavy dose of lead kept the valves from making contact with the cyl head for a good heat transfer and they burned, over and over again. Aircraft engine valves are different than what I could put in the VW’s.
Two strokes don’t have valves but I can’t help but believe that the very heavy dose of lead
will cause problems for you. The exhaust is very corrosive and will eventually clog any spark arrester on any saw. If it has a catalyst it will ruin it.
Avgas has a higher vapor pressure for operation at altitude, lead for anti-detonation and was designed for airplanes. Not dragsters or chainsaws.
JMHO
 
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