I recently got back into riding and bought an 1800s. Bike looks awesome and was told it had been stored for a few years so probably had bad gas... After many tanks and using multiple bottles of carb cleaner it still hesitates, backfires and all around runs like crap when I drive less than 60mph. I've brought it to multiple shops and have replaced the plugs, checked and changed the fuel filter, and hoses but nothing has worked. It has an aftermarket big air intake and aftermarket straight pipes. I've been told to find oem air intake but at a loss. Any used out there?