Chainsaws

The problem with using E85 is a little more complex than simply the rubber materials used. The engine need different metering to offset the air to fuel ratio needs of E85. Autotune and electronic fuel injection systems helps in this area to a point. The EFI systems for small engines are being developed but currently it has quite few problems just like the early fuel injected automobiles did.

As far having to rework carburetors due suspected E10 (ethanol based) or E15 (ether based) damage I found it is more related to the additives in the fuel oil than the fuel itself. I have used E10 and E15 in my personal equipment for years without problems. The most of the carburetor problems that come into my shop are from lack of use where the fuels have dried out completely leaving behind residues. Also the internal carburetor parts do wear out overtime. An example of this is the rubber check flaps of the fuel pumps. They wear out just like your automobile tires do. Some of the fuel pump diaphragms are made of mylar but suffer from same wearing.

Customers do have the tendency to buy the cheapest fuel oils available or incorrectly mix 2 cycle fuel. I have had several customers that had nothing problems with their 2 cycles even new ones until I get them to use a good professional oil mix of known good quality.

When it comes to aftermarket kits I have seen very poor quality materials used. I even had rubber gaskets to melt once exposed to fuels. This why I only use carburetor OEM repair kits besides these cost about the same or less than those aftermarket kit except those el cheapo Chinese knock offs. While the Zama and Walbro manufactures are based in China, they are offered no protection from these knock offs coming out China by other companies.