$35 Install of single clutch cable
$55 Install of throttle cables (pair)
$25 Lubrication and adjustment of all cables
WHAT IT DOES AND THE PROBLEMS
Your cables are the controls to your bike. They tell your bike how to transfer the power to your rear wheel. Whether it's your clutch cable, your throttle cables or, on older bikes, the brake cables, they all need lubricated regularly for proper operation.
The other factor is correct cable tension. Keeping the right amount of free play in the throttle and clutch is critical. Not enough free play in the clutch cable and you can end up with clutch drag, wearing out your clutch components prematurely. Not enough free play in your throttle and you don't get the response when you need it or you end up with high idles or inconsistent/unsafe riding.
WHAT TO LOOK FOR
Inconsistent throttle twist or clutch pull, sticky throttle, high idling, constant tension adjusting, rusted or broken cables.
HOW TO FIX
Lubrication helps cables slide easily in the casing, removing the dirt and grime that gets inside during the course of use. Cables naturally stretch with use so keeping up on adjustments is absolutely critical. While there are numbers as to how much free play is recommended, it is largely a personal feel. At times it may be necessary to completely replace cables because of neglect or age.