A motorcycle throttle that sticks while your riding can be annoying, but it can also be dangerous. Ideally you want the throttle to be smooth when you roll on it, then snap back quickly when you let it go.
So, why does a motorcycle throttle stick? Several things can be the cause. The throttle cable needs lubricating, it’s being pinched somewhere, cables need adjusting, or the bar ends are too tight. Let’s look at all of the causes and determine how to resolve them.
Lubricate the Throttle Cables
There are two cables associate with the throttle, one opens the carburetor intakes, and the other cable, attached to a spring, is responsible for snapping the throttle back when you let go. Over time, the original lubricants can become dry and dirty, causing the throttle cable to stick a little.
Inspect the cables at both ends to make sure there are no frayed wires. If there are, you should replace it.
Remove the cables from the throttle at the handle bars. You don’t necessarily have to remove them at the carburetor end, but, put a rag down to catch the lube that drips out the ends.
Next, using a throttle cable lubricator tool, found on Amazon, squirt some throttle cable lubricant down the housing until it comes out the other end.
Re-attach the throttle cable to the throttle and, hopefully, that will take care of the problem.
Adjust the Cable
Sometimes, if the cables are adjusted too tight, it will cause the throttle to stick a little. Also, a throttle should have a certain amount of free play, usually 2 -3mm. Check the owner’s manual for your motorcycle for the exact number.
Free Play: How far you can spin the throttle before you feel resistance.
Loosen the lock nut, then turn the adjuster nut in or out until you get the right amount of free play. Turning the adjust nut out will lengthen, or stretch the cable, reducing the amount of free play.
Next, check the cables where they attach to the carburetor. Loosen the lock nuts and turn the adjuster nuts so that the cable is snug, but still snaps back when you let go.
Check the Cable Routing
Sometimes the cables can be routed in a way that causes a pinch, or a sharp bend. This bend could be just enough to cause the cable to stick within the cable housing. Check the routing to make sure nothing is getting in the way.
Next, turn the handle bars fully to the right and to the left to make sure it isn’t pulling excessively on the cables.
Check Bar Ends or Throttle Lock
If your motorcycle has bar ends, make sure they are not too tight. I experienced this when I install new bar ends. I just kept tightening the up as much as I could. Suddenly the throttle was completely stuck. It was a simple fix. Loosen the bar ends so they don’t interfere with the throttle and you don’t end up with a sticky throttle again.
Throttle locks can cause similar problems. If you have a throttle lock installed, double check how tight it is. It could be causing the throttle to stick.
Clean and Lubricate the Throttle Tube
The throttle itself consists of a tube, either plastic or aluminum, that fits over the handle bar. The grip fits over the top of the tube, and the cable also attache to the tube. This is what the cables are attached to, an
Over time, dirt and grease can build up under the tube, causing it be feel sticky. You can remove the tube and the grip and clean off the handle bar and the inside of the throttle tube. Apply an all purpose grease to the inside of the tube when you reinstall it.
Also, check the tube for cracks and replace it if needed. This is an opportunity to upgrade your throttle tube to something more durable. Replacing the tube is a quick, easy job. You’ll need to remove the throttle housing and the cables to get the tube off, and slip on the new one.
Replace the Throttle Cables
Often the cables can be so worn or sticky that they will need to be replaced. Purchase a new set of cables specific to your make and model of motorcycle.
When you remove the old cables, take note of where they were routed and route the new cables in the same way. Adjust them so that the throttle does not stick, snaps back when you let go, and has a small amount of free play.
Is the Issue With the Carburetors?
If none of these steps fixed the problem with a sticky throttle, then your issue may be somewhere in the carburetors. You can visually inspect the springs where the throttle cable attaches, and make sure they are springing properly.
If the carbs are dirty it could cause the throttle slider to stick, or the air intake valves to stick. A sticky slider can sometimes be cleaned without having to remove the carbs from the bike. Try spraying WD-40 or a degreaser where the slider arm rotates. Turn the throttle several times to work it in and see if the sticky throttle is fixed.
You can try cleaning your carbs by running seafoam through them to clean out the varnish that develops over time. But, if this doesn’t work, the carbs will have to be removed for a thorough cleaning.
Test the Throttle
Once all the repairs and adjustments are done and you think you have the throttle behaving as it should, take it out for a test ride to make sure it’s operating properly. Take it up to full throttle and back down. Make slow left and right turns with the handlebars fully turned so make sure it doesn’t affect the throttle.
Throttle cable inspection should always be a part of your regular maintenance and your pre-season inspection. Keeping the throttle operating smoothly and avoiding sticky throttle issues will help keep your throttle hand comfortable on long ride, and will keep you safer.
Why does my motorcycle die when I give it throttle?
This is most likely caused by clogged pilot jets in the carburetor. Pilot jets are responsible for giving the carbs that initial supply of fuel right when you turn the throttle. Cleaning or replacement may solve the problem.
What if my throttle doesn’t have enough free play?
Without a sufficient amount of free play, the throttle may twist on its own, particularly when you turn the handlebars, which will pull on the cables.