Hi all, I recently purchased a yz250 that needed a top end.... The guy I bought it from, told me he cleaned the bottom end with gasoline, and re-installed the top end and ran it with an old piston. When I took the cylinder and piston off, I spun the crank, and saw some drops of gas come up on the crankshaft.... Wouldn't this mean he never ran the engine, because there is drops of gas coming back up when I spin the crank? Because if he would of ran the engine, wouldn't the remainings of gas from the cleaning, burn up from the heat of a running engine? Or can it be from kicking the bike over just to check the compression, and it sucked gas into the cylinder and went between the ring and cylinder gap and fell into the bottom end? Also, is it ok to run an engine with some little remainings of gasoline in the bottom end from cleaning it? Any help will be appreciated!!!