Help my engine!

[FlyingScot]

I have a 0-6-0 hornby engine that used to run fine but now it refuses to move. I don't know what motor it has but the problem is that it sometimes doesn't move, but sometimes it does move but I compared it's speed with similar engine on the same track and that engine went faster than the first engine. They were supposed to run at the same speed. It's tender driven if that helps. I think it's a magnet problem, am I correct?

 

[royaloak]

Sounds like its got the Hornby ringfield motor and yes the magnet does drop off after a while.
Plenty of places do spare parts, just google Hornby spares.