Welcome to the forum. How long have you had the bike, and is the poor fuel economy something new, or has it always been that way? There could be several things causing the problem; bad spark plugs, valves out of spec, a dirty carb, or possibly something else. Dirty carbs are the most frequently seen cause of poor engine performance.
Keepin' all the left over parts. Gonna use 'em to build another bike!
Have you looked in the tank to see if there is any rust? Installing an inline fuel filter is a good way to ensure any contaminants in the tank don't reach the carb. Fuel line is cheap, and you could replace it when installing a fuel filter if you think it may be a problem. I like the clear filters so you can see anything the filter traps. You can check fuel flow by turning the petcock to the off position, disconnecting the fuel line at the carb and placing the end into a clean, clear container and turning the petcock to on. If there are visible contaminants in the container or it is rusty orange in color, the carb will definitely need to be thoroughly cleaned.
It has peak power. I can cruise at 65-70 mph until the tank is dry. I put new tires on it a month ago and check the pressure Everytime I ride (everyday). I have already checked the chain as well. I will try adjusting the valve and see if that helps. Thankyou for your help.