If you decide to stay with the cable throttle control, it is possible to take all of the play and the incipient drift out of them with hardware store parts. I have done it and so has ghind (Greg) jim
basically a return spring on the motor throttle linkage. The spring should be as long as possible and as weak as possible to still keep the play out. ghind has posted some pictures of this spring on an e-tec. Do a search of his posts with spring as a subject. jim