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If you’re experiencing problems with your motorcycle’s acceleration or throttle response, the throttle cable adjustment is one of the first things to check.
Adjusting the throttle cable is much easier than repairing your carbs.
Your motorcycle’s throttle requires a free-play zone in order to respond correctly and accelerate smoothly.
You can find the exact amount of recommended throttle cable free play in your motorcycle service manual.
Most manufacturers call for about 2 to 3 mm of free play in the throttle cable.
The throttle cable will naturally loosen up overtime, so it’s important to check the throttle slack periodically.
A cable that’s too loose will have poor throttle response and may feel sluggish or weird at WOT.
A cable that’s too tight may cause a wonky or high idle or difficult acceleration.
Check the Condition of the Throttle Cable
The first thing to check is the condition of the cable itself.
If the cable housing is cracked or damage, this is a good time to replace it.
It’s also worth checking the routing of the cable.
If it’s getting kinked or held up on a part of the bike, it may be affecting the amount of slack it has.
This is also a good time to check the throttle’s return travel. When you let go, the throttle should close automatically.
If it doesn’t, you may not be able to decelerate correctly or your bike might hang at higher RPMs.
Sometimes this can be fixed through adjusting the cable, or it may be a symptom of a carb issue.
Check the Throttle Cable Slack
Remember, the throttle cable will loosen over time. This is something you’ll want to check periodically.
To check the throttle cable’s free play:
- Refer to the shop manual for the recommended amount of play (usually about 2-3 mm).
- Roll the throttle back and forth to find the “free play zone” where moving the throttle does not engage the cable.
- Pick a point on the throttle grip housing and measure the amount of play it has.
- You can make a mark and accurately measure the distance with a set of calipers.
Adjust the Throttle Cable
Your motorcycle will either have one or two throttle cables.
If it has two cables, one handles the opening of the throttle and the other handles the return.
Your throttle cables will have two points of adjustment:
- At the carb body.
- At the throttle housing on the handlebar.
If you need to make large throttle cable adjustments, start at the carb body.
If you need just a small adjustment, skip to the throttle housing.
To adjust the throttle cable:
- Loosen the locknut.
- Tighten or loosen the adjuster to get the right amount of play.
- Turning the adjuster in will give you more slack.
- Turning the adjuster out will tighten the cable.
- Tighten the lock nut.
- Confirm the adjustment.