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Still mystified how 2 cycles manage to keep working E10 or gasoline? Some web sites with chatter on this subject have surmised most professionals or high users that operate chain saws claim no problem with E10, just normal tweaking that they already do. A few posts of "visitors" with ridiculous claims of draining cups of water out of small tanks, yeah right.


Here is a post that will give you a good inside on chain saws and E10 problems.




The problem is not the E10. It's Dolmar shipping the saw set on the edge of lean for EPA with non-alcohol gas, and the dealer not re-tuning it.


Changing the oil mix isn't the solution - re-tuning the saw slightly richer is. Dolmar might say "more oil", but that's only because they can't tune them richer and pass epa...

That has been my experience and my suspicion, thanks for the heads up.


I have purchased several saws, weed wacks and yard tools over the last 4 years of several makes and Echo has been by far the worst for lean. All of our new Echos were so lean they can barely be kept running on our 10% corn fuel, Dealer checked out?? Ill ask the blond at the check out next time I need some lumber or hardware, LOL. Our MS660 was borderline at the limiters and I removed them to get a cushion adjusted, the 260 Pro has not been touched and seems good. A couple FS 110s were right on but are 4 stroke, imagine that?? Our TS400 was decent too. Great dealer been using for 27 years. The SHindiawa saws have not had a screw touched and are spot on, dealer or factory set I cant say?




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Two cycle owners probably the most vulnerable in fuel change such as gasoline, to E10, and to E15. The switch from E10 required chain saw tuning as well as the future switch to E15.


Note- E15 should not be more damaging to engines as compared. Why? The fuel change would require carb adjustment. The problem with E10, it allowed chain saws to operate (lean) with no adjustment. Better to have a big difference in fuel to require adjustment.


Root cause of problems with E10 for two cycles


- Foreign manufactures shipping saws tuned to petrol and dealerships merely selling saws. This problem may go away with E15 fuel.


- EPA regs limit or require blockage of carb adjustment with heavy fines if in violation i.e. meter jets instead of needle valve. These engines need to be modified. Good for them even with E10.


- EPA regs for fuel mix set per unleaded fuel requirements i.e. 50 to 1. Oil mixtures need to be evaluated for ethanol fuels. End of story.


EPA air pollution standards require minimum oil ratio that barely keeps 2 cycle lubricated. Any suboptimal conditions, the engine seizes. Ethanol can be utilized as bogy man with such problematic conditions. What will a dealer do? Blame EPA and tell the customer EPA standards destroying his saw and not to follow manufacturers recommendations or simply blame ethanol?


Dealers post of demise of most 2 cycle engines per stringent clean air regs. That a lot of manufacturers will close shop or sell the brand name to competitors. RedMax one of the few that is able to meet regs. Four cycle engines replacing two cycle engines. Others use heated catalytic converters. 


- Ethanol will absorb water. This is both good and bad. Good to absorb small quantities of water to keep system upon a continuous purging of minute water accumulation. Bad to try to absorb large quantities of water and suffer phase change as within this condition the engine will suffer from lean, lubrication, and operational problems. Of course we need not forget even with E0 water contamination is a common problem and similar damage results. Actually, minute water contamination a big problem for E0 fuel. E15 or 15% ethanol should make the fuel for forgiving upon water contamination.


Most professional operators have no problem with E10 as they have been trained to adjust carb carefully for atmospheric and fuel conditions. Something they needed to learn even before E10 fuel was on the scene. Also, they burn fresh fuel, mix oil carefully, and always shake fuel can before fueling. These are normal procedures expected with or without ethanol.


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This whole issue is why a year ago when 1 of my 3 saws (a Stihl) needed a new oiler and chain guide and the dealer told me it would be nearly as cheap to buy new as repair- I said- "thanks, but no thanks- fix it". I do not want a small engine that is jet change rather than needle valve AFR adjustable.


Where was this discussion going on at Flee?

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I think a lot of people blame ethanol for issues that would have happened no matter what fuel they were running on. Remember that DOE study from a couple of years ago.




A portion of the results from that study.


"Small non-road engine results include the following when E15 and E20 were compared with traditional gasoline:


As ethanol content increased:

Regulated emissions remained largely unchanged,

Engine and exhaust temperatures increased;


Engine performance was inconsistent, even with traditional gasoline;


Commercial engines, as well as more sophisticated residential engines, exhibited no particular sensitivity to ethanol from a durability perspective; and,


The effect of E15 and E20 on the durability of smaller, less expensive residential engines (e.g., line trimmers) was not clear given that a number of these engines failed regardless of fuel type."


I agree that professionals adjust the settings and that is probably a part of why the have less trouble with two stroke equipment than the general public. But the other part is that the general public buys equipment that is prone to failure no matter what fuel they use.

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Yes, remember that report now.  Pretty critical on run of the mill hardware quality two cycle engines. Rusty has done lots of experimenting with his weed whacker, especially with different oils.


The two cycle technology just about hit the wall of lower air emissions. More 4 cycle engines within this market for good reason.


I can think of no better hot zone for benefit than ethanol fuel for the two cycle engine.  These new engines should develop more power per cc engine displacement. They should run cooler which is always a problem for these engines. Emissions should plummet as ethanol ability to carry chemical oxygen a good fit within two cycles.  Marine engines should benefit from lower vapor pressure and danger of explosion of inboards. Fuel spill environmental impact should be greatly reduced. For the above benefits the fuel would need to be E100.


The more expensive engines would benefit greatly from turbo's which are getting more popular with small high performance engines. Chain saws have some thinking of copying model airplane engine technology and utilizing high engine rpm for shaft mounted turbine.  These engines will stroke 30,000 rpm. A big benefit to stop using crankcase for this. 2 cycles fail upon crankcase seals. Instead the crankcase would have oil. No oil mixing with fuel required.


Also, can imagine the exhaust heat would be tapped to vaporize the fuel and create pressure by thermal. Maybe a propane torch aimed at exhaust before startup. No conventional throttle plate required (more efficient). Just a valve to control ethanol gas discharge.

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