Hi,

Here is all you need to know about servicing a lima motor.

Otherwise you can buy a remotoring kit. These in my experience have very mixed results.

http://www.hakanpaa.net/susumotor_en.htm

I've 3 loos with lima motors and I've extra pickups on the wheel's which I found made a big difference to the slow running

You could try here for a replacement motor also:

http://diesel-trains.co.uk/Lima_replacement_motor_kits.html

or use an old cdrom drive motor even!:

https://chippedblade.wordpress.com/index/improve-the-performance-of-old-lima-motors/