Sorry not had chance yet the wife’s got me outside mowing and allsorts of stuff I really don’t wanna be getting on with. And now we’re on the routine lockdown walk happy days
So far I’ve taken both sets of belts off both sets of top pulleys move quite a lot but not rotate all the way around The middle double pulley rocksolid
If the cam doesn't fully turn the piston may well be at the top causing the valve to strike, don't force it.