These cable ends are normally hidden inside the throttle housing for protection from the elements and are often coerced to move through gentle bends of metal tubing attached to the throttle housing and then inside the housing while attached to the throttle tube. The push and pull throttle cables go through the same range of motion so in order to keep the movement smooth, you should regularly be lubing the cables and then cleaning them when it is time to relube them again. That includes the inside of the housing itself and throttle tube grooves that the cables sit in.
The cables themselves are strands wound together to create the cable just the same as cables in a suspension bridge. The finished cable itself when wound has no plastic sheath to protect it from the outer cable housing as it moves back and forth so we need to supply it with some form of lubrication. What products should you use?
Contact Cleaner: You are going to need something to get all of the road grime out. Bel-Ray makes a good brake and contact cleaner
Rags: While it is not the messiest bit of maintenance that can be done, you will want some shop towels to wipe up any excess drips.
First order of business is to remove all the free play from the throttle cables via the adjuster(s) close to the right handle bar. Then remove the screws from the throttle housing and open it up to disconnect the cables from the throttle tube (NOTE: you may not have enough free play to do this so you may have to detach the cables from the throttle bodies/carburetors). At this time, you clean off all grease and any debris from the throttle tube completely with parts cleaner. Inspect the throttle tube for distress from the cable in gouging fresh marks or grooves and inspect the cables for any fraying. Then clean the inside of the throttle housing and remove all dust and debris.
When the above tasks are completed attach the cable lube fitting to the end of one cable and lube the cable correctly. Don’t spend 30 seconds doing this and call it good. It will take several minutes to do the job right! A tell tale sign is that cable lube is dripping on the engine and then onto the floor. Not pretty I know but you know the job is done! Remove the cable fitting and place high temperature grease on the exposed ends of the cables.
Next, rebuild the throttle housing systematically making sure that the cables are routed correctly around or behind the right hand fork and that the barrel ends are correctly positioned in the throttle tube. Once the throttle housing has been bolted back together in the correct location on the handle bar, check the operation of the throttle. Make sure you don’t push forward to accelerate and make sure the throttle turns smoothly in both directions! Reinstall the housing screws and tighten to the correct torque and check the movement of the throttle one last time for a smooth opening and snap back.
Assured that the cables are installed correctly, now go to the cable adjusters and set the free play in the cable to your desired setting between zero throttle and actually pulling the cable to open up the throttle bodies/carbs.
NEVER start the bike until you have gone past this step!
Once done with this task, start the bike and let it idle. Move from lock to lock to make sure the idle doesn’t rise. If it does, gradually put more free play in the cable until the idle does not change from lock to lock. Once that has been done, tighten up the lock ring or nut on the cable(s) and the job is done. You will notice a huge difference!
Dave Moss is the Founder of Catalyst Reaction and Host of OnTheThrottle video programming specializing in technical analysis and how too segments. He has been working with street, track and race riders and motorcycle suspension and chassis geometry since 1995 and has become an in industry internationally recognized authority in his field through his work with regard to testing and tuning. Dave is an avid rider and races with AFM in Northern California.