Without knowing the mechcanical condition of your ride, I will go out on a limb here. Your heads, piston topsand valve area are most likely to have a high carbon build up in the combustion area. This does 2 things. 1. This condition can create a higher compression ratio requiring the the higher octane use to prevent knocking. 2. This carbon build up can also cause a preignition condition because the carbon starts to glow or ignite the compressing fuel before the correct timing can fire the spark plug at the correct time in the compression stroke. The higher octane rated fuel has a higher flash point than the lower grade 87 octane. All you are doing is masking the the concern of carbon build up that is the root of your issue. Regarding E85 fuels I would not risk trying it due to the alcohol content that will mess up you rubber parts in the fuel system. The alcohol will cause the fuel needle tip to swell and not allow fuel into the float bowls. It will weaken the other rubber parts as well and cause a failure. Not worth the risk of certain failure. Best to correct the underlying issue of carbon build up. Besides I can bet the head gaskets if have not been replaced yet will fail due to age. Fix it right now and it will not let you down when you least expect it.my 83 runs like crap on the low octain regular gas so all i can run is premium so you know e85 has the higher octain rating & around here it's about 90 cents cheaper a gallon it was a idea didn't know if it was a good one so run the idea past some people that would know still can't ride scince my surgary looking for things to try seeing i have all the time in the world to exparament
I agree with what these folks are telling you, PAF. markgeath explains it with everything I've been taught or read about it.has anyone ever tried to run e85 in there bike?