1983 9.8hp stiff throttle control on tiller handle

Hello folks, this is my first post and with a question. As the title says, I own a 1983 9.8hp short shaft. The throttle operation is very stiff to the point of being dangerous. With the engine cowl removed, I notice that there is considerable play between the throttle cables when the throttle is increased and then decreased. Moving the throttle on the tiller handle back and forth slightly causes the cables to flex a lot. The binding appears to be a slide type assembly that is mounted above the carb. I have attempted to lubricate the cables by spraying lubricant into the cable openings and into areas where the throttle linkage contacts the carb, but it's still very stiff. What would be the solution? I have a manual, but this doesn't seemto be covered. Any help is appreciated. Thanks, Robert