Learning throttle control on your dirt bike is one of the trickiest parts to successful riding whether you're on the track or trail. Combine that with the clutch and brake system you see why it takes long hours and hard work to just finish a race.
But when throttles go bad you can go nowhere fast or just about anywhere even faster.
The most common throttle problems a rider encounters is a broken throttle or a sticky throttle. Any number of reasons can impact the performance of the dirt bike's "gas pedal" including bad maintenance or damage from an impact. "Whiskey throttle" however is all in your head. For the uninitiated, "whiskey throttle" is giving your bike too much throttle, then you start to loop out, panic, and give it even more throttle instead of powering down.
A broken throttle is usually quite evident and typically occurs after a crash or from the careless dropping of the bike. If the dirt bike lands on the throttle control side (right), a broken throttle tube can result and generally getting power to the bike is no longer an option.
Poor routine maintenance also affects throttle performance when dirt, gunk and other debris builds up around the tube and housing and causes sticky throttle. Additionally, the throttle cable, just through general wear and tear, stretches, breaks, or, thanks to the dirt build-up, gets sticky, too. A stretched throttle cable won't give your bike much life and obviously a broken cable doesn't work, but a sticky cable or throttle tube can produce these kinds of results:
Sometimes the throttle cables can, overtime, twist and bind or just be routed incorrectly. This also inhibits throttle performance. You might not notice a clear and present issue right away from twisted cables so what happens is you'll feel it on a turn when the movement of the handlebars jostles the throttle cables. You might suddenly get a surge of unexpected power resulting in a crash, or the bike powers down so you open the throttle then the cables untangle and we know what happens after that.
The throttle cable is also linked with the carburetor and where the two connect also affects throttle control. If the connection between the cable and carburetor is damaged or stuck with muck expect similar results as noted above. Again performing routine maintenance and ensuring proper adjustment between the throttle cable and carburetor prevents this issue.
Believe it or not, new grips can interfere with proper throttle control either from the grip glue seeping in between the throttle tube and handlebars or wire tying the grips overly tight (this generally happens on plastic or nylon throttle tubes) pinches the tube to the handlebars causing it to stick. When adding new grips don't use excess glue and check for any overflow before riding. If glue turns out to be the problem try scraping it out first or if necessary use an appropriate solvent but don't be surprised if your grips dry up or melt since most cleaning solvents contain corrosives. So, just don't use too much glue!
Routine maintenance is always the answer to keep a throttle working and this should include a pre-ride inspection. When you open or "twist" the throttle and release, it should be smooth and snap back "closed" without any hesitation. Open and close the throttle a few times and check the feel. Any stickiness should be addressed prior to a day of riding.
If you need replacement parts, Motion Pro makes a number of throttle accessories including this kit that includes the tubes, cables and four reel sizes. Other considerations include Pro Taper throttle tubes. Check out the full dirt bike throttle accessories page for additional selections.
Whoops, this rider is headed for the dirt
Like all things Motocross, throttle control issues are not necessarily cut and dry. A pre-ride check doesn't always uncover a sticky throttle and as luck would have it the problem can occur in the middle of a Moto.
Most riders, especially in the middle of a race, either tend to force the issue by applying pressure to the throttle or may not even know a problem exists especially if they're going bar-to-bar on the last lap. In either case, they loop out and the checkers go to their competitor. A broken throttle tube from a small crash also might not reveal itself right away only to impair power to the bike or really start working at the wrong time so be conscious of that post-crash during a Moto.
However, the bottom line is nearly all throttle problems can and should be taken care of prior to riding. You can cause serious injury to yourself and others. Make sure your throttle is operating correctly before riding and perform all necessary maintenance. If you're new to the sport, it's wise to get a professional or someone with loads of experience to offer help and guidance when dealing with cable wiring and installing new grips.
Written By: AndrewT