Hello, my 77 xs 750 has been setting for a couple years. Somehow vacume carbs let gas into cylinders and air filter box. So my crankcase had 1 gallon of gas in it. I draind it but i still can´t get it to turn over. Did the gas mess up the bearings or maybe swell the clutch plates and are my seals and gaskets shot? When in first gear, clutch in, bike lunges forward. In N i can´t move the kickstart. Should I consider the engine toast, rebuild or replace? Bike only has 9k on it and in very good shape. Thanks for any input