30-07-14, 07:53 AM
I think this problem is mostly from an ancient blocked air filter causing the bike to run rich. New air filter and new plugs would probably be a good idea too as I'd guess the ones in the bike are probably sooted over. A carb clean couldn't hurt but I don't think it's the main problem as dirty carb with blocked jets would be leaning the mixture not causing it to run richer and dropping the mpg so badly.