[Ho Lee Kow]

So ther is a diffrent chassis with large motor with magnet in it. I wonder how to change to small motor if possible or how to know what chassis and motor I get if I buy. If I buy a 914 and has magetic motor in it can I change to non-magnetic motor? Sorry for my English, a friend used to edit me! He in anotherr flat maybe at work mostly. There is many that use no magnets.