Because motorcycles are smaller than cars and much more basic, every component on them is very important. This includes the throttle. Without it, you wouldn’t be able to accelerate.
When a motorcycle throttle sticks, it can really give you an uneasy feeling. This is an issue that should be immediately addressed to ensure your safety and prevent any damage to your motorcycle.
What should you do if the motorcycle throttle sticks? If the motorcycle throttle sticks, pull on the clutch, shift to neutral, and turn off the motorcycle. Do not turn on the motorcycle until the issue is resolved. Inspect and clean the throttle and the throttle cable.
I’ve owned several older motorcycles and have run into this problem a handful of times. Being a motorcycle enthusiast with a background in mechanical and automotive engineering, I can give you a helpful guide as to what you should do when your motorcycle throttle sticks and how you can fix this problem.
Addressing A Sticking Motorcycle Throttle And How To Fix It
These questions concerning a sticky throttle is probably 50/50. People are wondering what to do if they accelerate and their throttle sticks to the open position, meaning it’s stuck in acceleration mode. In this case you will struggle getting it to slow down. The other half may be wondering about a throttle that won’t accelerate at all because it’s stuck in the closed position.
It is a much more dangerous situation if your throttle is stuck in the open position because your motorcycle will continue to try and accelerate. It is especially dangerous if this spontaneously happens while you’re out for a ride.
If your throttle is sticking to the open position, do not attempt to turn on the motorcycle until the issue is resolved. Trying to start at such a high rev isn’t good for your motorcycle.
If your throttle sticks to the open position while you’re out on a ride, apply the brakes and steer yourself to a place where you can stop. Pull the clutch and shift into neutral then turn off your motorcycle. You will need to find an alternative way to get it home.
If your throttle is sticking to the closed position, you can still start your motorcycle but it will just idle and you won’t be able to accelerate. If the throttle becomes stuck in the closed position while you’re out on a ride, you may be able to putt your way home on back roads if you’re close enough. Otherwise, you’ll need to find an alternative way to get your motorcycle home.
I’ve owned dozens of motorcycles through a motorcycle restoration business I used to own. I restored some pretty rough bikes and most of them had throttle issues. I’ve learned a few tricks that can easily fix this, but I’ve also learned why this happens in the first place.
Once you get your motorcycle home, you will need to inspect the throttle and the throttle cable and assess for damage or sticky build-up. Take the whole throttle assembly off the right handle bar. See if there is any gunk built up inside of it or if any wires are crossed that would make the mechanism tight.
In either case, you should thoroughly clean out the throttle while it’s off. Be sure to also clean the part of the handlebar that the throttle connects to. Over time, a lot of deposits can build up inside and cause the throttle to stick.
If the issue is not the throttle itself, the next thing you’ll need to check is the throttle cable. If the cable sleeve is old and has cracks in the rubber, you should replace it. Dirt, metal shavings, and all sorts of garbage can get down into the cable sleeve (the black rubber that covers the cable) and binds up the cable which may be the reason you can’t move your throttle back and forth.
If the cable looks decent upon inspection, you can buy some cable lube and squirt a little bit into the cable covering at the end of the cable. You’ll then need to slide the cable back and forth so the lube can reach the whole inside of the covering.
The throttle and the throttle cable are the usual culprits to a sticking throttle cable. But if you have tried cleaning and/or replacing the throttle and cleaned the cable and it’s still sticking, you can also check where the cable connects to your carburetor.
There are little springs and clamps that hold the end of the throttle cable that become too tight; this prevents the throttle from being able to move back and forth. If needed, replace or clean these springs and clamps to ensure your throttle has the appropriate range of motion.
If you’re still having issues with your motorcycle trying to accelerate despite your efforts of cleaning the throttle and its cable, there may be another underlying issue. You can learn more by reading our article “6 Reasons Why Your Motorcycle Accelerates By Itself.“
What To Do If The Throttle Won’t Spring Back To Idle Position
Alright, so you may have found yourself fixing your throttle and feel like you have gotten out all the dirt that was causing it to stick in the first place. However, after a good cleaning, it’s pretty common to see a motorcycle throttle move but doesn’t do it’s natural spring back to the idle position when you let go of it.
Though you still have control over how your motorcycle reacts in a situation like this, it can still be potentially dangerous and should not be ignored. If you lose grip on the throttle, the motorcycle needs to slow down through that natural spring back (which is a safety mechanism engineers purposely made). In this case, the motorcycle wouldn’t slow down and will maintain it’s speed.
If you’ve gone through all the previous steps of cleaning everything that has to do with your throttle but you’re having issues with the throttle not springing back, your likely culprit is a loose throttle cable (a problem that won’t be fixed by cleaning it). Tightening a loose throttle cable is easily fixable. All you’ll need to do (on most motorcycles) is adjust the lock nut found just right off the throttle where the cable runs out of.
When The Throttle Spins But You’re Not Accelerating
A phenomenon that’s often associated with a sticking throttle is that after you feel like you’ve fixed it, the throttle spins but you’re no longer able to accelerate. It almost feels like the throttle is very loose.
If this is happening to you, it most likely means your throttle cable is broken or is not connected to the carburetor at all. A broken throttle cable can be difficult to diagnose because it may be snapped somewhere inside the sleeve which is hard to see.
If this is happening to you, you’ll need to replace your throttle cable. Throttle cables are inexpensive anyway, so having a new one will ensure your safety.
How To Prevent A Motorcycle Throttle Cable From Sticking In The Future
Regularly applying cable lubrication to the throttle cable is one way to prevent a sticking motorcycle throttle. This should be done about once a year. You’ll notice that when you do this, some black nastiness may come out at the end of the cable sleeve.
As disgusting as it may look, it’s also a bit satisfying knowing you were able to get all the gunk out before it caused any problems. If you routinely do this every year, you can make those cables last the whole life of the motorcycle and you’ll never need to replace them.
Another way to prevent a sticky throttle is properly covering your motorcycle when it’s not being used. Properly covering your motorcycle will prevent dirt and other unwelcomed garbage from getting inside the throttle and throttle cable that make it stick.
Most of my motorcycle restorations had been sitting outside in the elements for months or even years. Every single one of them needed a new throttle assembly, something that could have been prevented from a simple motorcycle cover.
Conclusion
Having a sticking throttle on your motorcycle is not only a nuisance, but it’s also potentially dangerous. If your throttle is stuck in the acceleration position, pull on the clutch, shift to neutral, and turn off the motorcycle. It’s best to not attempt to turn on the motorcycle again until it has been fixed and/or cleaned.
Having run into this issue many times myself, I have found that a thorough clean usually does the trick. A little bit of dirt can create such havoc, so it’s very important you properly cover your motorcycle and shield it from the elements. Where were you guys when your throttle started to stick? Feel free to share your stories and help our fellow riders!
Related Question
Why does a motorcycle lose power when accelerating? A motorcycle can lose power when accelerating because of plugged jets in the carbs, a broken carb spring, a vacuum leak, a carb spring that’s on backwards, extra slack in the throttle cable, and poor timing advance. See my article here for more information.