Same old problem occured this week so thought sod it it needs to be sorted which I have done this morning.
Removed the Motor and stripped down, removed the drive shaft, cleaned out the crud and greased up. Found the shaft a bit of a twat to remove as I don't have a vice to hold the motor.
Once replaced it runs better than it has since I got the Beast.
No special tools really necessary but as I have a Soldering Iron I removed the PCB so as to avoid damage.
Job done in approx 1 1/4 hrs.