If the fan belt is there sometimes a bit of tension added by pushing on the belt with one hand and a tug on a fan blade with the other works. I have just enough room on the 270 to slip a socket over the Crank bolt, and other times when trying to get things that feel stuck moving I've used a large screw driver or pry bar on the fly wheel from down below and moved it a few teeth in both direction gradually going further each time...
