have a chance to buy a 680 but the motor won't run what would be approx cost to rebuild this motor.

 

A little more info would be nice,do you mean a Rincon? If a quad that new needs a rebuild, it was probably beat to holy hell and never maintained, plus you have that Hondamatic tranny, if that was abused, that would be another small fortune. What makes you think it needs a rebuild? just not running could be anything, bad fuel pump, coil, bad gas, bad sparkplug, give us a little more info, and we can help you out. What is the general condition of the quad? did the owner take good care of it? what happened to make it stop running?