What octane gas for chainsaws?

Just wondering if using high (93) octane gas in a Poulan pro chainsaw will help performance/lifespan or harm it? Also, is it ok to use fuel stabilizer in small engines such as chainsaws, weed eaters, and leaf blowers?

[Andrew Mackey]

Hi Octane gasoline does not run hotter, as most people think. It actually runs cooler. Using 93 in the Poulan, won't hurt it, but it won't help it either. In fact it may cause the exhaust port and muffler screens to carbon up quicker, due to the lowered temperature. Fuel stabilizers work well. Keeping the engine fuel tank filled to the top, and running the machine (no matter what it is) once a week, for 5 minutes, will keep the seals and the carb, clean and lubricated, as well as drive moisture out of the engine and ignition system. This applies to both 2 and 4 cycle engines! Either empty or completely fill your fuel can too. A partially filled can will attract condensation, and allow fuel volatiles to escape and evaporate. Even with fuel stabilizers, gas won't keep for ever.
Andrew

[Andrew Mackey]

WARNING - For the users of 2 cycle engines: CHECK YOUR FUEL SOURCES ! I was buying gas at a local Hess station, and happened to glance at a tiny new(1"x2") label on the pump. It read: "This product contains 10% Ethanol, for use as a motor fuel only" This is Gasohol! Gasohol is lethal stuff for lean mix 2 cycle engines, as the ethyl alcohol destroys the lubricity of the oil in 2 cycle gas. A 16:1 mix engine might survive an encounter with this 'contamination', but a 32:1 of a 40 - 50:1 would probably sustain damage form insuffecient lubrication, using this fuel.
For the 4 cycle engine users (you 2 stroke guys too), Gasohol is hydroscopic - that is, it attracts moisture. If you have a partially filled steel tank, or gas can, this fuel will attract more moisture than usual, leading to rust. Also, even in a plastic tank, the moisture in the air will degrade Gasohol's performance rapidly, due to the ethanol's moisture attraction. I do not know if fuel stabilizers work as well in Gasohol either, due to the fact that the alcohol has a higher evaporative rate than gas alone.
If you use Gasohol in an auto or truck, you will get a 10% loss of engine power, as well as up to a 20% loss of fuel economy. My 1996 Dodge truck, with the 5,2 L V8 went from 15 MPG to 11 MPG, using the same brand of fuel, before the change over/ after the change over. I had thought it was an engine problem, but after switching brands (regular gas), the milage went back to the 15 MPG after a few tank fills. In most states, Gasohol must be plainly labeled, I guess that NJ is not one of them.
Andrew

[K D Redd]

Yes, stay away from gasohol. It will eat-up the carb also. I have been told by a Stihl dealer to use 89 octane , mid grade. Worked on a HUSKY that was burnt up from using 87 octane. Need new jug and piston. Had less than 50 hour on it. Dealer would not fix because of fuel issue. Most two stroke oil have a fuel stabilize in them. The Poulan Oil I use does.

Kent

[PeteB]

I have a Stihl 310 chainsaw. It calls for 89 octane or better. I believe they warn against detonation with regular 87 octane....and engine damage can occur. Good as this thing works, I sure don't want to damage it...ran it all day today and it purrs like a kitten.
Pete

you gatta watch sometimes on that high octain sometimes, it'l dry out the diaphrams in the carburator quicker than with a normal octain gas, something you would usually run in a mower or something.. something lead usually took care of... made things last a wee bit longer.....

[BDMelon]

89 octane for chainsaw works the best with stihl & stihl mix has stablizer in it already

[ldj1002]

Originally Posted by Andrew Mackey

WARNING - For the users of 2 cycle engines: CHECK YOUR FUEL SOURCES ! I was buying gas at a local Hess station, and happened to glance at a tiny new(1"x2") label on the pump. It read: "This product contains 10% Ethanol, for use as a motor fuel only" This is Gasohol! Gasohol is lethal stuff for lean mix 2 cycle engines, as the ethyl alcohol destroys the lubricity of the oil in 2 cycle gas. A 16:1 mix engine might survive an encounter with this 'contamination', but a 32:1 of a 40 - 50:1 would probably sustain damage form insuffecient lubrication, using this fuel.
For the 4 cycle engine users (you 2 stroke guys too), Gasohol is hydroscopic - that is, it attracts moisture. If you have a partially filled steel tank, or gas can, this fuel will attract more moisture than usual, leading to rust. Also, even in a plastic tank, the moisture in the air will degrade Gasohol's performance rapidly, due to the ethanol's moisture attraction. I do not know if fuel stabilizers work as well in Gasohol either, due to the fact that the alcohol has a higher evaporative rate than gas alone.
If you use Gasohol in an auto or truck, you will get a 10% loss of engine power, as well as up to a 20% loss of fuel economy. My 1996 Dodge truck, with the 5,2 L V8 went from 15 MPG to 11 MPG, using the same brand of fuel, before the change over/ after the change over. I had thought it was an engine problem, but after switching brands (regular gas), the milage went back to the 15 MPG after a few tank fills. In most states, Gasohol must be plainly labeled, I guess that NJ is not one of them.
Andrew

Andrew,
Set me straight on moisture and ethanol. I thought ethanol is alcohol. Alcohol gets water out of your gas tank. For years in anything where I can't get water from your fuel tank because it hasn't got a drain in the low point, I pour a little acohol right in the tank. After a very short while the water in fuel problems would go away. Maybe I am mistaken about ethanol being alcohol. Don't get me wrong, I am not saying using gasohol is good. I have never used it knowingly. I don't know how alcohol gets rid of the water but I know it does in both diesel and gasoline tanks. If alcohol attracts moisture, how did my water problems disappear?
L.D.

[Andrew Mackey]

Ethanol is alcohol. Yes it got rid of your water problem, and that is the problem It absorbed the water into the fuel. This water then in turn goes thru the carb, or in autos the injecters, and then is burned in the engine. The problem lies mostly when you shut down the engine. Ethanol is hell on fuel pump internal parts, injecters (chemical erosion from galvanic activity brought on by alcohol and water in contact with metal parts) , and rubber diaphrams in most carbs is degraded by the alcohol. Also, any alky - water that is vaporized, and left in contact with iron or steel will cause rust. The alky will also attract more water from the atmosphere into the fuel, or onto parts than usually enters, it gets into your tank thru the tank venting system. As your engine runs, air enters tank as fuel level drops. As I posted earlier, the alky also degrades lubricity of 2 cycle oils, which can lead to engine burn out. My neighbor just burned out his new Poulan saw - had less that 10 hours on it. He used Hess gas, from a local gas station (10% ethanol). When the poulan dealer aske what brand fuel he used, and where he got it - refused to honor warrenty, due to substandard fuel use - gasohol not reccomended fuel. I managed to free stuck engine, with Kerosene and SAE 50 oil mixture soaked overnight, and turned flywheel with a pair of Channel lock pliers. I drained kero after engine loosened up, easily turning over with starter, and put in different brand of gas @ 16:1, instead of 40:1 recommended. The engine runs OK, but bearings are noisy, and compression not 100% It may run a little better after run a while, but warrenty is gone. Hess now has larger labels on pumps - 2 x 5 inches, right next to pump price label. I filled car and took 300 mile trip to conn. Got 16 MPG for trip. Filled there with regular gas, no alky, - got 23.6 MPG for trip back - same route exactly! Go figure
Andrew

[K D Redd]

The problem is the goverment is pushing the addition of ethanol to all gasoline to extend supply. They are ramping up production of ethanol here in Missouri.

Kent

[Jim Metzger]

I offer this from my experience. I live in an area where the only gas available is blended with ethanol and this has been the case for the last 10 years. I have yet to have an engine failure due to using this type of gas in any engine both 2 and 4 cycle. I usually add about 20% more oil to the gas than is called for in 2 cycle string trimmer, chain saw and leaf blower applications. I then adjust the carburetor so that they almost 4-cycle all the time, in other words as rich as possible without loosing power. It must be remembered, no matter how much oil you add to the gas, this mixture must pass through the small holes in the carburetor jets. So no matter only a certain amount of oil will do some good for lubrication. I use only oils that are rated TWC-3 or better. The problems I do have in both 2 and 4 cycle engines is that if left in the carburetor for long periods of time the carburetor will start to leak due to the ethanol eating through the aluminum turning the carburetor into junk and being un-fixable. I learned the hard way to drain this gas if I am not going to run the engine for long periods of time. I used to add a gas stabilizer in the good old gas days and this would take care of problems, but not so with the new gas. I also found out that when running old engines at engine shows in the hot weather that the new gas will make the engine run much leaner and vapor lock and refuse to start in some cases. All in all, the new gas is not as good as the the gas it replaces and has fewer BTU's per gallon thus taking a lot more of it to do the same work thus the poorer gas mileage in cars & trucks. I am not even conviced that it better for the environment.

[Andrew Mackey]

I second the last posting on the new fuel. You cannot tell me that an engine uses twice the amount of fuel, and that it runs cleaner. I had a 1966 chevy Impala Super Sport. Had a high performance 327 engine. With a Rochester Quadrajet carb, it constantly got 24 MPG, and on a trip to Florida, averaged 28 for the trip. Mr parents had a Ford Grenada - 302 engine. Got 10 MPG tops, and the government says this is better?
Andrew