A dirt bike’s kick start is a vital part of the machinery. It provides motion to the engine to power up and run smoothly. However, if your four-stroke kick start is stuck, this can be a major problem.
If your 4 stroke kick start is stuck, it could be due to a seized piston, jammed gear teeth, dirt and debris in the crankcase, or a seized transmission. Besides, a bent shaft or broken spring can cause the kick start to jam. Easy fixes include cleaning the clogged parts and replacing damaged ones.
Most people have been in a position where they cannot get their kick-starter working again. If you’ve ever had this experience, this article is for you. Read on to learn more about why your kick start might be jammed and how to fix it.
8 Causes Why Your 4 Stroke Kick Start Is Stuck
Arguably, it’s crucial to know the potential causes of a kick start jam. This helps you identify the appropriate remedy each time you face this problem.
Here are eight reasons a four-stroke kick start can get stuck:
1. The Piston Is Seized
The piston is a crucial part of the engine. It provides motion to the four-stroke cycle, allowing the ignition system to produce sparks and ignite fuel for combustion. Like any other mechanical device, a dirt bike’s piston is susceptible to damage.
For example, if you haven’t maintained your dirt bike properly or damaged it, the piston can seize. As a result, it may not move, causing the kick start mechanism to jam. This results in the kick start being unresponsive and immobile.
2. The Gear Teeth Are Jammed
The gear teeth work with the kick start mechanism and engine to produce forward motion. If the gear teeth are stuck, they can prevent your bike’s kick start from moving.
If you apply pressure to the kicker-lever and it feels like it’s working against something, this is a clear sign that your gears aren’t shifting correctly. In such a case, it’s advisable not to continue kick-starting the dirt bike, as it may damage the gears.
3. Dirt and Debris in the Crankcase
The crankcase holds all of the dirt bike’s moving parts. If the crankcase is full of debris, this can prevent your kick start from moving.
When you apply pressure to the kick-starter lever, it should rotate freely over a short distance before encountering resistance due to the engine’s compression of air and fuel. However, if there’s too much dirt and debris in your dirt bike’s crankcase, it’ll result in too much resistance on the kicker-lever, causing it to jam or break off completely!
4. The Transmission Is Seized
Transmissions play a significant role in powering up the engine for movement. Any dirt bike’s transmission is composed of multiple gears which work together to provide forward motion.
If your dirt bike’s transmission is seized, it will disrupt the power transfer from the engine to the rear wheel. This can also cause your kick starter mechanism to jam or break off altogether. You’d then need to get your transmission fixed before you could continue kicking.
5. The Kick Starter Spring Is Snapped
A spring provides resistance against a lever when it’s in motion, helping you control how quickly and how far it travels back into position once pressure has been released.
With time, dirt bikes’ kick-starter springs become deformed and stretch out due to constant pressure placed on them by the kicker-lever. If your dirt bike is old or hasn’t been maintained properly, the spring may snap—rendering the engine unresponsive.
6. Kick Start Shaft Is Bent
The kick-starter shaft is connected to an arm on the side of your dirt bike’s engine, which moves back and forth as you push down on the lever.
If your four-stroke dirt bike’s kick start assembly is stuck due to a bent shaft, this can cause trouble for you during startup. A bent shaft can prevent your gear teeth from lining up with each other appropriately. It can also render your transmission useless if it breaks off completely.
7. The Kick Return Spring Is Broken/Faulty
The kick return spring provides resistance against the kicker-lever as it makes its way back into its original position. As a dirt bike owner, you should know that a broken or faulty kick return spring can cause your dirt bike’s engine to seize up completely!
When your kick start lever is stuck and cannot move, check to see if the cable has snapped first—that could be the problem. However, if your cable is fine but you still can’t get your bike to start, the return spring may have snapped off or become damaged over time. You’ll need to replace it before you can continue kicking.
8. A Component of the Kick Start Assembly Is Missing
Sometimes you may have lost or misplaced a piece of the kick start assembly that’s required to get your dirt bike started. If any of these components are missing, you won’t be able to kick start your dirt bike at all.
You’ll need to locate the component before you can continue kicking. That said, here are a few signs that a piece of your kick start assembly is missing:
- The kick starter lever can’t move any further down, or it doesn’t have enough power to push the kicker-lever past a certain point.
- You’re using all your energy to get your dirt bike kicked, but it just doesn’t want to start.
- Your kick-starter mechanism makes a loud clicking noise as you try to power it up.
- You hear a rattle if you shake the kick-starter mechanism.
- A piece of the assembly doesn’t look like it fits appropriately.
- The kick return spring isn’t as tight as it should be.
- The kicker-lever doesn’t have enough tension to go up.
Note: If any of these symptoms are present, check for components that may have fallen off your kick start assembly. If loose parts are lying around close by, chances are they fell out while you were kicking your dirt bike!
5 Ways To Fix a Stuck Kick Start
Having looked at the common causes of kick start jamming in four-stroke engines, let’s examine how to fix each of them. However, before attempting any fixes, ensure that you’re in an open area where it’s safe to work on your dirt bike. Also, check to see if any small parts may have fallen off while you were kicking your dirt bike or trying to get it started.
Here are a few ways to fix a four-stroke kick start that has jammed:
1. Clean the Piston, Gear Teeth, and Crankcase
As I mentioned, dirt and debris in these components can get stuck between moving parts, causing them to seize up. Before you can unleash more force on your kick start mechanism, clean out all the dirt and debris on the piston, gear teeth, and crankcase.
You can clean the mentioned components by following these steps:
- Take apart your dirt bike’s kick start assembly while the engine is cool.
- Use compressed air to blast away any loose dirt and debris in the crankcase.
- Spray some WD-40 on these components to remove any rust or corrosion—which can cause them to stick.
2. Lubricate the Kick Start Lever
If there’s not enough play in your kick starter lever, it may get stuck when you try to move it back and forth. This is because the metal-on-metal contact becomes too much for the kick start gear teeth or crankcase to handle.
That said, lubricating your kick start mechanism could free it up. However, before you lubricate the kick start lever, ensure that your dirt bike is turned off and cool. Doing so prevents any accidents or injuries that may happen if there’s still flammable oil in the crankcase.
When you’re ready, follow these steps:
- Place your dirt bike on the ground and take off the kick start mechanism.
- Lubricate the lever with some WD-40.
- After lubricating the kick-starter lever, reattach it to your dirt bike before testing it out.
Tip: If you want to maintain the best possible performance from your kick start, lubricate it regularly—just don’t forget to take it apart first!
3. Ensure That the Kick Starter Spring Is Tight
As I mentioned earlier, your kick starter spring is responsible for pushing the kicker-lever past a certain point. As such, it needs to be tight and consistent for your kick start assembly to work correctly.
If you can’t hear or feel the spring when you pull on the kick starter lever, then this may mean that it’s too loose. If that’s the case, then you’ll need to adjust it.
Here’s a video demo of how to wind the kick start spring correctly:
Note: Ensure that your dirt bike is turned off and cool before removing the kick start assembly. Also, you’ll need to remove one of your dirt bike’s footpegs.
4. Replace the Faulty Kick Start Spring
If your kick starter spring is broken or faulty, then you’ll need to install a new one. Here’s how to replace a defective kick start spring in four steps:
- Undo the nut on top of your kick start mechanism using a wrench like this Olympia Tools Wrench (link to Amazon). It’s adjustable, making it ideal for various applications. Besides, it comes with a durable, corrosion-resistant alloy steel construction.
- Remove the worn-out kick start spring.
- Thread the new kick start spring onto your kick start mechanism.
- Use a wrench to tighten the nut on top of your kick-starter assembly until it fits snugly.
5. Replace the Damaged Kick Start Lever
So, you looked down at your 4-stroke dirt bike’s kick start lever and realized that it’s broken? No worries! It’s not the end of the world. Replacing a broken kick starter lever is pretty simple.
Follow these five steps to help you replace a broken kick starter lever:
- Place your dirt bike on its stand so that it’s stable.
- Undo the nut on top of your kick start mechanism using a wrench.
- Remove the broken kick start lever.
- Thread the new kick start lever onto your kick start mechanism.
- Use a wrench to tighten the nut on top of your kick-starter assembly until it fits snugly.
4 Stroke Engine Maintenance Tips
Now that you know how to fix your 4-stroke dirt bike’s broken kick start, you should also know the proper way to maintain it. Here are a few tips that you can use to keep your 4-stroke engine running smoothly for years to come:
Change Your Engine Oil Regularly
Changing the oil in your dirt bike’s four-stroke engine takes care of several problems and dangers. For example, changing the oil reduces wear on your piston and cylinder coating, prevents dirt and debris from getting into your engine’s mechanical parts, and ensures that you’re riding a dirt bike that runs as efficiently as possible.
However, if you don’t take care of it now, this will cause more damage to your dirt bike’s engine in the long run.
Make Sure Your Air Filter Is Clean
In addition, it’s essential to ensure that your air filter isn’t dirty. If the air filter has collected a lot of dust and debris, then you need to clean it out with a damp cloth. Once you’re done cleaning it, use some compressed air or a vacuum cleaner to get rid of any excess grime or moisture before re-installing it into your dirt bike’s four-stroke engine.
Replace Spark Plugs Regularly
When buying new spark plugs for your dirt bike, ensure that they fit your dirt bike properly (for instance, ensure that they have the same number of threads as your old spark plugs). You should also remember to replace your dirt bike’s spark plugs regularly. Otherwise, this will cause massive trouble for your four-stroke engine.
Check Your Controls Regularly
Other than that, you must check all of your dirt bike’s controls regularly. This includes inspecting and tightening any bolts on your tires, brakes, fork/swingarm, and footpegs as necessary.
In addition, this also means making sure that all of your light switches work correctly and are functionally connected (for example, most bikes come with turn signals and brake lights).
It’s crucial to be proactive when taking care of your 4-stroke kick start. If you don’t take proper care of this mechanism, it’ll cause significant damage to your engine, resulting in a much more frustrating experience for you.
However, there’s no need to panic if you end up with a broken kickstart lever. Just follow the steps I’ve mentioned, and you’ll be good to go. If you’re unsure how to fix your four-stroke, ask for professional help.
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