Gas Mileage Problem

[Guest]

I have a 1981 gs650. shaft drive, 18.160 miles and just had it tuned up. It has a little bit of light backfiring when it first starts it but then it runs smooth. I burnt 3/4 of a tank while driving a 30 mile highway stretch and I kept it under 60MPH. I installed new plugs wires, changed the oil and filter, air filter and tried seafoam, and it made no difference. Any ideas would be appreciated........Thx

[mmattockx]

What is the current jetting? Stock pipe? What do the plugs look like? Either you are leaking fuel somewhere (like the crankcase) or you are so rich it shouldn't run. I get ~48mpg (Imperial gallon, I am in Alberta) in mixed riding with my 1100E with pods and pipe on it, so that is as bad as things should ever get. At less than 100km/h I would get well over 50mpg.


Mark