RS Cosworth Analogue Replacement Motor

[RayWood]

I have a Scalextric set from circa 1995 with 2 RS Cosworth cars. One of the cars works fine but the other only moves a couple of inches on the track before stopping. On investigation the motor contines to whir but the drive shaft stops turning after a couple of rotations. So I'm guessing that I need to replace the motor. I'm very new to doing maintenance of these cars so not sure what motor I need or the best place to get it from. Not being a modeller I want to keep it as simple as possible i.e. preferably no soldering although if that is only way then OK with doing that. Thanks in advance for any advice.