Hi All, We have a circa 1965 MF 50 tractor with a 4 cyl perkins diesel. When parked up it was running perfectly, but after leaving it for 3 or four weeks she wouldn't even turn over ( Just a solenoid click). I Have removed the starter which checked out OK). I attempted to turn the flywheel with a crowbar but it won't budge. Has been regularly serviced, has good oil pressure and has never got hot. Any suggestions on fixing this would be greatly appreciated.