How To Fix A Lawn Mower Throttle Cable?

A working gas lawnmower is essential for a gardener to keep the grass immaculate. Because modern lawnmowers work so reliably, it is easy to assume that they will continue to work; it is frustrating when they don’t work well.

If the throttle cable breaks, cut off the broken end and use a shorter throttle cable, or if broken further along, replace the cable core. If the throttle cable has stretched, you will need to shorten it, and if it becomes obstructed or bent, you need to replace the throttle cable.

The lawnmower throttle cable is arguably the most straightforward part of the engine; however, it needs to work optimally, or it will have a disproportionate impact on the machine. If it is broken, the engine won’t run, and if it is stretched or obstructed, the Lawnmower will not generate full power.

Ways To Fix A Lawn Mower Throttle Cable [Depends On The Problem]

Two areas can break, each requiring a different action to fix it.

If the lawnmower throttle cable breaks very near either end of the line, there is a good possibility that you can fix it.

If the cable breaks further away from either end, you must follow the steps below.

Fix Lawnmower Throttle When Cable Is Broken Close To Either End – Step By Step Installation

If the cable snaps near the end of either side of the cable, follow the steps below.

1. Remove the side which is not broken.
2. EITHER remove the cable from the throttle control. It is usually a “Z” joint that can be maneuvered out of the attachment point.
3. OR remove the throttle cable from the attachment to the throttle arm on the carburetor.
4. Check the end which is broken and measure it. If it has snapped off less than an inch from the end, you can fix the throttle cable.
5. When the cable is removed, carefully slide it out of the sheath covering it.
6. Cut one inch of sheath off.
7. Squirt WD40 oil into the sheath until it starts to flow out of the other end.
8. If the broken end of the cable is frayed, cut the frayed ends with a pair of sharp wire cutters, carefully cut the frayed part off.
9. Feed the cable back into the sheath until each end sticks out.
10. Identify the broken end of the cable.
11. Using two pairs of needle nose plyers, carefully bend the end into the same shape “Z” bend as the broken piece.
12. Reattach the throttle cable and test the action.

Fix Lawn Mower Throttle Cable [Broken Further Away From The End]

If the cable has snapped further than one inch from either end, you will have to replace the line.

You can purchase a new lawnmower throttle cable, which comes pre-attached to a new throttle lever assembly [Amazon], or fabricate a new one by taking the following steps.

1. Purchase a roll of stainless steel braided wire.
2. Remove the old wire from the protective sheath.
3. Carefully measure the correct length the new cable needs to reach.
4. Squirt WD40 oil into the sheath until it starts to flow out of the other end.
5. Thread the cable into the sheath until each end sticks out.
6. Study the ends of the previous cable and replicate the shape onto each end of the new line.
7. If you struggle to bend the same shape into the cable end, preformed versions are available on Amazon.
8. Reattach the throttle cable to the Lawnmower and confirm the action is correct.

Fix Lawnmower Throttle Cable Stretches

Over time throttle cables stretch, bend, and move resulting in the cable not rotating the throttle arm sufficiently. The result will be a lawnmower engine that does not achieve full RPM and seems underpowered.

You can test this by manually manipulating the throttle arm. The throttle arm is attached to the throttle cable at the engine. Pull the throttle arm entirely back with the engine running and verify that the machine can run at maximum revs.

If it revs at full power, the throttle cable is not pulling it far enough.

Depending on the model lawnmower, you can adjust the cable position or lawnmowers that do not have an adjustment mechanism; you will need to shorten the cable manually.

If your Lawnmower has a cable adjustment mechanism, consult the lawnmower manual to determine how to adjust it.

If there is no way of adjusting the cable length on your Lawnmower, take the following steps.

1. Remove both ends of the cable from the Lawnmower.
2. Choose the end of the cable you will cut. The best way to choose is to study the cable end attachments and determine which one you can best replicate.
3. Cut the cable an inch away from the chosen end.
4. When the cable is cut, carefully slide it out of the sheath covering it.
5. Cut one inch of sheath off.
6. Squirt WD40 oil into the sheath until its starts to flow out of the other end.
7. If the broken end of the cable is frayed, cut the frayed ends with a pair of sharp wire cutters, carefully cut the frayed part off.
8. Feed the cable back into the sheath until each end sticks out.
9. Identify the broken end of the cable.
10. Using two pairs of needle nose plyers, carefully bend the end into the same shape “Z” bend as the broken piece.
11. Reattach the throttle cable and test the action.

The Lawnmower Throttle Cable Movement Becomes Obstructed

If the lawnmower cable does not show any apparent damage, but the action is very stiff, check if the line is bent or obstructed.

1. Remove the cable from the throttle arm and test the throttle arm for free and precise movement.
2. If the throttle arm moves smoothly, check the cable by sliding the braided wire up and down the sheath.
3. If it is restricted, the cable may be bent and rubbing against the sheath, or contaminates have entered it.
4. Pull the wire out of the sheath and check its condition.
5. If there are no bends or fraying,  squirt WD40 oil into the sheath until it flows out of the other end.
6. Rethread the wire into the sheath and check if the movement has improved,
7. If the action hasn’t improved, the most cost-effective way to fix it is to purchase a new throttle cable.

What Function Does A Lawnmower Throttle Cable Serve?

Depending on the lawnmower model, the lawnmower throttle cable’s purpose is usually two fold.

1. The lawnmower throttle cable acts as the off and on switch for the engine
2. The throttle cable controls the speed at which the motor runs and, therefore, the rotational speed of the lawnmower blade.

The Lawnmower Cable Acts As The On/Off Switch

With most lawnmowers, pulling the throttle completely back will starve the engine of the fuel and cause it to cut out.

The Cable Controls The Speed Of The Lawnmower Engine

The Lawnmower’s throttle cable connects the throttle control attached to the handle and the throttle arm on the lawnmower carburetor.

Pulling or pushing the throttle cable changes the angle of the throttle arm.

The throttle arm is attached to the butterfly valve (throttle plate) inside the carburetor.

When the angle of the butterfly valve is changed, the amount of gas entering the carburetor is varied. The result is that the amount of fuel entering the piston chamber through the inlet valve is adjusted.

It results in less fuel/air mix for the combustion cycle and reduced engine revolutions.

These are the circumstances in which a lawnmower cable cannot correctly adjust the angle of the throttle arm.

Is it better to repair or replace a lawn mower throttle cable?

It is always better to replace a lawn mower throttle cable when the cable wears out. Also, using a new cable is always better than a repaired one.

How long do lawn mower throttle cables last?

A throttle cable generally lasts for around 5 years. However, it also depends on how much your lawn mower is being used. The more you use the lawn mower, the more wear you would see.

What does a throttle cable do?

The role of throttle cable is to control the engine and blade speed. Using your mower at full throttle makes it more efficient.

Conclusion

A broken, damaged, or tight lawnmower throttle cable will prevent the lawnmower engine from operating optimally. The great news is that each of these issues is easy to fix, and the cost involved is minimal.

You don’t need to be a licensed lawnmower technician to fix a throttle cable that isn’t working.

You need to follow a few basic diagnostic processes to trace the root of the problem and undertake the steps in this article to correct the situation.

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