No - the hammer won't work....
Where are the rough spots; this engine does not like rough spots... Are you trying to just turn the flywheel without any air pressure applied to the engine ?
What oil are you using for lubrication? - try different oils, starting with thin and moving on to thicker - mine runs best with diesel engine oil.
There's a problem with using thicker oils though - they provide a better seal (and stickier spots for spectators to rub off their faces ) - but introduce a lot of drag on the engine to overcome viscosity.