Bosch is a great saw. Is that an older model. I am suprised to see a problem with the Bosch. A saw should not smoke, so my guess is it is damaged. Anytime you have smoke, you are going to have friction which means a loss of power and will cause it to wear out a lot sooner. Now you could have a problem with the motor. Have you oiled the motor. Usually worm drives have a splace for oil which is easy to add. try this first. The connection, usually copper and that is what could be smoking. If the oil doesn't take care of it, try to blow it out with a compressor, you might just have saw dust in the motor. If this doesn't work, let me know and we can try some other stuff.
