Well seeing as it takes more E85 to make the same amount of power as regular ole petrol it would damage you motor would be my guess.
E85 systems use a sensor to sense the fuel, when it sees E85 the computer changes the fueling requirements so that the motor gets the right amount fuel and also adjusts the spark curve.
Seeing as the 636 is not set up as a flex fuel vehicle running E85 would cause damage, and probably over a very short amount of time. you can run a mixture of ethanol in your fuel, something less than 10% if memory serves me right.
The problem for us is the ethanol is a solvent as well as a fuel. I don't think our gaskets and hoses are meant to handle ethanol and it might degrade all the seals in the engine and fuel tank. Also, since it's such high octane (105, I think), it might not burn as efficiently as gasoline.
Stick to regular gas and save yourself a big repair bill.
A forum community dedicated to all Kawasaki motorcycles including the ZX-6R, KLR 650, Ninja 250, Ninja 250R, and Vulcan. Come join the discussion about performance, modifications, troubleshooting, maintenance, and more!