Lawn mower crankshaft bent. How Much Does Lawn Mower Repair Cost
How To Know if Mower Blade is Bent
Most lawn mowers are less complicated machines – with a spinning blade powered by an engine. Like other tools, they require proper maintenance to make them keep working. If there is part of the equation that is out of sync, you will have trouble using your mower.
A lawn mower blade is one of the vital parts that should be sharp and well-balanced to cut the grass effectively. However, your mower will not cut the grass right if the blade is bent. Besides, it turns into a liability – mostly for your health.

Bent lawn mower blades give you higher-than-normal vibrations and uneven cuts. The best thing is knowing the causes of bent mower blades to prevent experiencing the problem.
This article will look at how to know if mower blade is bent and other related topics; read on:
- How to Know if Mower Blade is Bent
- 1. Uneven Cut
- 2. Excess Vibrations
- 3. Strange Noises
- 4. Lawn mower stalling
- How a Lawn Mower Blade Bends
- Fixing Bent Lawn Mower Blade
- Avoiding Bent Lawn Mower Blade
- 1. Understand Your Yard Layout
- 2. Comb Before Mowing the Yard
- FAQ: How to Know If Mower Blade Is Bent
- Can I get a bent lawn mower back into shape?
- How do I decide my lawn mower needs a new blade?
- What makes the lawn mower blades bend?
- Author
How to Know if Mower Blade is Bent
There are different techniques to identify a bent mower blade. You need to know these symptoms to fix the problem correctly – and safely.
Here are the signs of a bent lawn mower blade:
Uneven Cut
A lawn mower is designed to cut the grass evenly. When you look at the lawn after you have passed the lawn mower and realize an uneven grass cut, there is a higher chance of a bent lawn mower blade.
In addition, it may look as if it’s a hacksaw has done it. So, with an uneven cut, you will see that the blade requires sharpening. Another thing you may want to check is when there is a deterioration of grass quality.
Excess Vibrations
While mowing, there are vibrations to experience. A small amount is normal, but with a significant increase in vibration, something is wrong with the lawn mower. One of the problems could be a bent lawn mower blade.
fix BENT “crankshaft on lawnmower” in 10 minutes (straighten)…
When the lawn mower blade is bent, it will be unbalanced, leading to additional vibrations.
Strange Noises
If you hear grinding noises in your mower, that could be a bent blade. These sounds are from the underside of the deck. It is a sure sign of a bent lawn mower blade, requiring fixing.
Lawn mower stalling
When you continue using the lawn mower, there is a higher chance of damaging the crankshaft even after the blade is bent. The bent lawn mower crankshaft damages the engine; therefore, the mower keeps stalling.
Other Parts to Check for Damages
After checking the blade, there are other key parts of the lawn mower to check too. That’s because replacing a damaged blade may not solve the problem completely. There could be other parts already damaged and require fixing. They include:
If you find one of these parts damaged, you will have to fix them before using the lawn mower again.
How a Lawn Mower Blade Bends
While mowing the lawn and you hit a rock, stump, or another hard object, there is a higher chance for blade bending. Remember, the blade is spinning at high speed, and after it collides with a solid object, there won’t be a good mix.
You must flip your mower to know whether the blade is damaged.
Fixing Bent Lawn Mower Blade
You can easily solve the bent lawn mower blade with no other parts affected. Straightening is one of the solutions and is ideal for the environment.
However, the method has a downside: the chances of straightening it properly are slim. And if you don’t achieve that, you will still use a bent blade which may bring more problems.
The other solution is replacing the mower blade with a new one. To do that, remove the spark plug or disconnect the battery. Then you can tilt the lawn mower and proceed to remove the blade.
The replacement blade must be of the same size and correct center hole. Place it correctly up and secure it.
Avoiding Bent Lawn Mower Blade
You need to take necessary precautions to avoid bent lawn mower blades. That said, check here for some of the tips to guide you later.
Understand Your Yard Layout
Knowing the yard’s layout can be a great way to avoid experiencing bent lawn mower blades. You can easily spot the obstacles while mowing. Some of the obstacles are not visible, such as tree roots or stumps.
Understanding the yard layout enables you to know where there is permanent danger. So, when mowing, you will do it more carefully.
Comb Before Mowing the Yard
The step above ensures you are aware of all dangers in the yard. However, there could be other temporary obstacles that could damage your mower. These could be toys from your kids, a rock pulled by your dog, or other obstacles.
Before you start to mow, walk around your lawn, picking up obstacles you find on the way.
FAQ: How to Know If Mower Blade Is Bent
Can I get a bent lawn mower back into shape?
You can gently bend the lawn mower into shape, and it becomes straight again.
With an anvil handy, put the non-bend part under the anvil. Use the channel locks to bend the blade back gently.
How do I decide my lawn mower needs a new blade?
A general rule of thumb, you should replace the blade after one or two years. That will depend on use and performance purposes. Another reason is when bent, it has dents or is dull after sharpening it twice.
What makes the lawn mower blades bend?
Hitting a stump, rock, baseball, or large sticks can cause the blade to bend. These are some of the causes.
How to fix a vibrating lawnmower after hitting a tree stump or rock. Straighten a lawnmower shaft.
When working with a lawn mower, safety comes first. A bent lawn mower blade will be a big headache. It will help if you minimize the possibility of getting into trouble.
Therefore, understand how to know if mower blade is bent.
Know where permanent obstacles are located, such as drop-offs, tree stumps, rocks, and more, to avoid bent lawn mower blades. And when you experience bent blades, the ideal solution is to replace them with a new blade.
Author
Hi, I’m Ricky. I’ve been involved in lawn care and landscaping from when I was 15. To be honest, I didn’t like the idea of pushing mowers, collecting grass clippings, and maintaining flowerbeds at the time. But having seem the passion my parents had for gardening and outdoors and the effort they put in maintaining the health and beauty of our landscape, I couldn’t help but not only admire their hard work but also I became a part of it. As someone who loves to spend time with nature’s best, I find myself learning a lot more about gardening and outdoors on a daily basis. Not to mention I love to share the knowledge I’ve gathered over the years with my readers at We Mow Dallas. To be clear, I don’t have a Master’s degree in gardening or anything like that. Everything I’ve learned about gardening, landscaping, and lawn care spring from passion and engagement with my parents. And with a ton of free information out there, plus the ability to run tests and determine what works best for lawn care and landscaping, every day is an opportunity to learn and implement something new. My goal with We Mow Dallas is to teach you exactly how to maintain your lawn and landscape. And since I walk the talk in reality, you shouldn’t hesitate to join me in this wonderful world of landscaping and lawn care. View all posts
When a lawn mower is on the fritz, homeowners may want to consider investing in lawn mower repair instead of purchasing a new mower. Lawn mower repair costs between 40 and 90, or 60 on average.
By Timothy Dale | Published Jun 16, 2023 11:48 AM
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A lawn mower is a necessary piece of any home’s lawn-care maintenance equipment. This machine is designed to cut the lawn to a specified length, making the yard more appealing for the homeowner, residents, and any guests. Keeping the grass trimmed throughout the year also keeps weeds in check, prevents insect infestations, encourages improved root growth, and helps the lawn dry faster, reducing the risk of anyone slipping on wet grass.
So when the lawn mower isn’t working properly, it’s necessary for a homeowner to repair the machine as soon as possible to avoid dealing with an overgrown lawn or needing to pay professional lawn mowing costs. Experienced DIYers can handle some lawn mower repairs, but most people will need to hire a lawn mower repair professional to fix the machine. According to HomeGuide, repairs typically cost 40 to 90, though the average cost is about 60. Homeowners can use this guide to learn more about lawn mower repair cost factors to help determine whether the mower should be repaired or simply replaced with a new model.
Factors in Calculating Lawn Mower Repair Cost
Most lawn mower repairs cost just 40 to 90, but the cost of the repairs can vary depending on several factors, including the mower type, repair type, repair location, and tradesperson experience. Homeowners can find out more about lawn mower repair cost factors below to get a better idea of the budget required for lawn mower repair.
Mower Type
There are four common types of lawn mowers that are frequently used to maintain yards of various sizes, including push mowers, reel mowers, riding mowers, and self-propelled mowers.
- Push mowers rely on a gas engine to drive the cutting blades, but the user still provides the physical power to move the lawn mower over the grass. These machines weigh about 60 pounds, and repairs typically cost about 25 to 70.
- Reel mowers are completely manual. The user pushes the mower from behind, turning the wheels of the mower, which in turn drives the rotary pusher and cutting blades through the grass. These mowers have a basic design that can typically be repaired for about 10 to 50.
- Riding mowers are made for large yards and user convenience. The user can sit up on the mower, relying on the powerful engine and transmission to drive the movement of the mower as well as the rotation of the cutting blades. The repairs for riding mowers cost the most of any lawn mower type, so users should expect to pay about 100 to 250 on average.
- Self-propelled mowers work similarly to push mowers, except that they have a transmission to drive the wheels forward with minimal effort required by the user. This feature is great for large yards, but it can also increase the cost of repairs. Homeowners can expect to pay about 25 to 100 for self-propelled lawn mower repairs.
Repair Type
A range of issues could cause the lawn mower to malfunction. The cost for lawn mower repair depends heavily on the type of repair required to get the mower functioning properly again. Common repair types include replacing the air filter, replacing the fuel filter, changing the oil, sharpening the lawn mower blades, replacing the spark plugs, and tuning up the engine.
Severe problems with the lawn mower can lead to high repair costs that greatly exceed the average cost of common lawn mower repairs. For instance, while a simple carburetor cleaning may cost between 36 and 50, it can cost as much as 500 to 900 for a professional to repair the crankshaft of the mower. Homeowners can troubleshoot the problem and speak to a repair professional to get an estimate based on the type of repair.
Repair Location
A lawn mower doesn’t have the same convenient mobility as a car or truck, so when something goes wrong with the machine, the user needs to either pay for a repair technician to come to the home or load it up into a car or truck to take to the repair shop. If the repair technician needs to come out to the home, the homeowners can expect to pay a higher price for the repairs.
Homeowners can also expect the cost of lawn mower repairs to increase during the busy times of the year when the demand for this service is at its highest. With this in mind, it’s recommended that the homeowner take the lawn mower in for annual servicing during the early spring or late fall months, when the demand is lower. Choosing the right time of the year for service can help homeowners get a lower price for any required repairs.
Tradesperson Experience
Another factor that can affect the cost of the lawn mower repair is the experience of the repair professional. Repair technicians who are relatively new to the field will often charge less for their services, so if the lawn mower needs only a minor fix, like a spark plug replacement, it could be advantageous to seek out a less experienced tradesperson.
However, if the lawn mower has a more serious issue, it may be in the homeowner’s best interest to pay a little more, knowing that the professional repair technician has a significant amount of experience dealing with small-engine repairs. Before hiring a lawn mower repair professional, homeowners are advised to spend some time researching local repair companies and individual contractors.
Repair vs. Replacement
Minor lawn mower repairs are often worth the expense to get the machine up and running again, but when there is a serious issue, it may be a better idea for a homeowner to invest in a replacement lawn mower.
- Repairs are effective options for dealing with relatively simple issues, such as cleaning the carburetor, sharpening the lawn mower blades, changing the oil, replacing the spark plugs, changing the air filter, replacing the fuel filter, or tuning up the engine.
- Replacement becomes a serious option when there is a significant problem with the lawn mower, such as a cracked crankshaft, transmission failure, blown head gasket, or blown engine. In this case, the homeowner will want to look into the best lawn mowers that fit within their budget.
Before investing in a new mower from one of the best lawn mower brands, homeowners are advised to determine the cause of the problem so they can decide on the best option for dealing with the lawn mower. Homeowners will want to keep in mind that while a new lawn mower ranges in cost from 160 to 3,000, many lawn mower repairs can be completed for about 40 to 90. Even the best cheap lawn mowers will typically cost more than that.
Lawn Mower Repair Cost by Type of Repair
The cost to repair a lawn mower depends heavily on the type of repair. Fixing something minor or performing a regular tune-up won’t typically cost a lot, but if the head gasket is blown or the transmission requires replacement, the repair cost could be significantly higher. Homeowners are encouraged to find out the average cost of common lawn mower repairs near them to ensure the repair company is providing a service at a fair rate. To do so, they can call several lawn mower repair companies in their area and compare quotes. Below are the national average costs of lawn mower repair based on type.
Blade Sharpening
Lawn mowers are made for cutting through tough grass, but if the blades are dull, the mower may struggle to cut areas of the lawn with thicker patches of grass. This can overwork the engine, leading to overheating and excessive fuel consumption, so it’s recommended that homeowners have their lawn mower blades sharpened at least once a year.
The ideal time for lawn mower blade sharpening is just before the first mow of the season. This allows the user to get the most out of the mower before it is put into storage at the end of the season. Lawn mower blade sharpening typically costs about 50 to 70.
Carburetor Cleaning
The carburetor is the part of the lawn mower that is responsible for mixing the air and gasoline. If this part is dirty or not operating properly, the user may notice black smoke coming from the lawn mower exhaust. This typically occurs when the carburetor introduces a higher percentage of gasoline into the fuel mixture.
Lawn mower repair professionals will generally charge about 36 to 50 for lawn mower carburetor cleaning. If the problem is not resolved, it can lead the engine to backfire, overheat, or have difficulty starting. Additionally, the carburetor may fail, forcing the user either to invest in a new mower or pay for replacement parts and repair services to replace the carburetor.

Crankshaft Repair
Crankshafts are one of the more costly parts of a lawn mower to repair, ranging from 500 to 900. A crankshaft is intended to act as a bridge between the pistons and the flywheel. If the crankshaft is cracked, bent, or warped, the lawn mower will have a hard time starting.
Once it is started, if the crankshaft is broken, the mower may not be able to drive the cutting blades, and it could also overheat, causing the engine to shut down. This is because the crankshaft uses the up-and-down movement of the pistons to crank the flywheel in a circular motion, which in turn powers the fan belt and the transmission.
Head Gasket
A blown head gasket in a riding mower is often not worth the investment to repair given that it can cost between 1,200 and 3,000. If a riding lawn mower has a blown head gasket, it’s recommended that homeowners invest in a new lawn mower instead of paying to repair the existing one. A mower can still operate with a blown gasket, as long as the gasket is still able to facilitate enough compression within the system. However, the problem will get worse the longer it is left unresolved, leading to low power output, low compression, oil leaks, and excessive smoke from the exhaust; in some cases a blown gasket may prevent the engine from starting at all.
Motor Repair
Issues with the lawn mower motor can range in severity. Minor problems may cost only about 65 to fix, but if the mower needs a full engine replacement, it can cost more than 1,000. The engine is easily one of the most important parts of the lawn mower. This component is responsible for producing the power necessary to drive the cutting blades.
In self-propelled and riding mowers, the engine also provides the force needed to propel the mower forward, instead of relying on the physical strength of the user. With this in mind, if the user notices any issues with the motor, it’s recommended that they speak to a repair professional to determine if it is worth it to repair the motor or if it would be best to invest in a new mower.
Rotary Pusher Repair
Not every homeowner has a mower with a gas engine. Some people still rely on basic reel mowers with a simple rotary drum and cutting blades to tackle small lawns. However, if the rotary pusher cracks, warps, bends, or otherwise becomes damaged, the lawn mower cannot function properly.
Users will want to take the lawn mower to a local repair company to determine if the rotary pusher can be repaired or if it will need to be replaced. Typically, homeowners can expect to pay about 40 for rotary pusher repairs. This low cost is one of the reasons some individuals prefer basic reel mowers.
Transmission Replacement or Overhaul
The transmission is an important part of the lawn mower and can cost between 200 and 500 to replace or overhaul. Push mowers and reel mowers don’t have transmissions, but self-propelled mowers and riding mowers rely on transmission systems to power the wheels and drive the mower forward.
If the transmission is having issues, such as grinding gears or starting and stopping during operation, or if the wheels are not rotating with the pulley, the transmission may need to be replaced or overhauled. Overhauling a transmission means a professional will need to remove, disassemble, and rebuild the transmission, taking time to inspect each part for wear or damage. Any parts that are damaged or that show substantial wear will need to be replaced with new parts when the transmission is being rebuilt.
Tune-Up
One of the best tips for homeowners to keep a lawn mower in working order is to take it into a repair shop or have a professional come out to the home to tune it up. This service is an important preventive measure to help ensure the lawn mower continues to function properly for years to come. Typically, users will spend about 130 on average for a thorough lawn mower tune-up.
However, DIYers may be able to get away with spending as little as 10, while it can cost up to 250 to have a professional tune up a heavy-duty residential riding mower. The cost of the service varies depending on the type of mower, the condition of the mower, and the local labor rates.
Do I need lawn mower repair?
Lawn mowers and other power equipment for the yard will typically start to show signs of wear before a problem occurs, such as an oil leak, vibrating engine, or smoking exhaust. Similarly, if the average job completion time starts to steadily increase, this can be an indication that the mower isn’t operating as efficiently as it once was.
Inoperable or Vibrating Engine
The clearest sign that there is an issue is if the lawn mower won’t start or if the lawn mower keeps dying. While this may be due to something as simple as low fuel levels, it could also indicate a problem with the spark plugs. Experienced DIYers can try to replace the spark plugs to resolve this issue, but if this doesn’t work, it’s recommended that they take the mower to a lawn mower repair professional.
Similarly, excessive vibration could indicate that the lawn mower has a bent or loose part that needs to be repaired. It could also be a sign that the engine is on its last life, so homeowners are advised to speak to a repair professional to find out if the mower can be repaired.
Oil Leaks
Oil is intended to keep the various parts of the lawn mower properly lubricated. This helps the components move and reduces the heat caused by friction. If the lawn mower does not have enough oil, the moving parts of the machine tend to wear out faster, so if the user notices an oil leak, it’s important that they have the issue repaired before using the mower again.
A lawn mower may leak oil due to a crack in the seals or gaskets. It could also be caused by a loose plug or pan. However, if the mower is also producing black smoke from the exhaust, the engine could be cracked, leading to more costly repairs.
Inconsistent Performance
Another sign that the lawn mower may need repairs or servicing is if the machine seems to operate inconsistently. Lawn mowers are designed for cutting thick grass so that homeowners can maintain the functionality and appearance of the yard. If the user notices that the lawn mower slows down significantly when they reach areas with thicker patches of grass, this may indicate that the mower is due for a tune-up.
The homeowner will want to inspect the lawn mower for any signs of wear and consult with a knowledgeable repair professional to determine the cause of the inconsistent performance. The issue may be as simple as dull cutting blades that need to be sharpened, though engine problems could also affect the performance of the mower.
Unusual Noises
A lawn mower is supposed to make a low droning noise as the blades whip around to cut through the grass and weeds. However, if the mower is making a loud screeching, knocking, or rattling sound, this could be an indication of a serious issue. Screeching sounds from the engine typically indicate that there is a problem with the engine belt. Professional repair technicians can replace the belt to resolve this problem.
A knocking sound can indicate that the mower has a bent blade or that there is a broken mechanism in the engine. Similarly, a rattling sound often indicates that a part has come loose or shifted out of place. It’s recommended that the homeowner stop using the mower until a repair technician can figure out what broke, bent, or came loose. Otherwise, the parts could cause further damage to the mower.
Smoking Exhaust
The exhaust of a gas mower can sometimes smoke after the oil is refilled. This is typically due to the user overfilling the oil. However, if white smoke is spilling out of the exhaust, it may indicate that the mower has a worn-out gasket or that there is a problem with the carburetor. The carburetor is the part of the mower responsible for controlling the mixture of air and gasoline in the engine.
If the carburetor is not functioning properly, there may be a higher percentage of gasoline in the mixture, leading to the smoking exhaust. Replacing the air filter could resolve this issue, but if this doesn’t work, a professional repair tech may need to repair or replace the carburetor.
Excessive Oil or Gas Consumption
Older lawn mowers and mowers that are in poor condition may start to consume oil or fuel at a higher rate than normal. If the user notices that they are having to refill the lawn mower with oil or gas more frequently than usual, there may be a problem with the mower. Ongoing wear can lead to a lower efficiency level in older mowers, but a newer model that’s experiencing this problem may have an issue with its spark plugs.
Incorrectly firing spark plugs mean the lawn mower needs to consume more oil or gas to operate properly. Replacing the spark plugs may resolve this issue, but if the problem persists, the homeowner is advised to take the mower to a lawn mower repair professional for servicing.
Lawn Mower Repair: DIY vs. Hiring a Professional
When it comes to lawn mower repair, there are many tasks that can be handled by an experienced DIYer. Depending on the skill level of the individual, they may be able to complete an entire lawn mower tune-up, including replacing the spark plugs, switching the air filter, changing the fuel filter, changing the oil, cleaning the mower, and sharpening the cutting blades.
This can be a great way to reduce the cost of lawn mower repairs, though the drawback is that there isn’t any guarantee on the work, so if the DIYer makes a mistake or uses a faulty aftermarket replacement part, they will be stuck with the responsibility of resolving the problem.
If the lawn mower is experiencing a serious issue, like a blown head gasket, it’s recommended that the user leave the repair to a trained professional lawn mower repair technician. While this will cost more than purchasing replacement parts and handling the repair as a DIY job, there is a better chance that the repair will be successful. Additionally, a trained pro from one of the best lawn mower repair services will typically complete the repair in a shorter period of time than an inexperienced DIYer, allowing the homeowner to get back to their yard care and lawn maintenance more quickly.
How to Save Money on Lawn Mower Repair Cost
Most lawn mower repairs won’t break the bank, with an average cost of just 60, but there are some problems that can be significantly more costly to resolve. So that users can avoid emptying their wallet to pay for lawn mower repairs, it’s a good idea to think about ways to save money on lawn mower repair costs. Consider these potential options to keep the lawn mower in good working condition while also keeping repair costs low.
- DIY simple repairs and service. Instead of hiring a professional lawn mower repair technician, a DIYer can complete a variety of minor repairs, reducing the overall cost of lawn mower upkeep.
- Research and get quotes from multiple companies. If the mower does require professional repair, make sure to research at least three different companies to ensure that they offer a fair rate for the service.
- Purchase replacement parts separately. Lawn mower repair costs are typically split into labor and parts. Depending on the problem, homeowners may be able to purchase replacement parts separately to reduce the cost of the repair.
- Keep up with regular lawn mower maintenance. The best way to avoid costly lawn mower repairs is to stay on top of regular maintenance tasks, like changing the oil, replacing the air filter, and cleaning the mower.
Questions to Ask About Lawn Mower Repair
Knowledge is important when hiring a company or an individual. The more the customer knows about the service, the better chance they have of getting the best value for the job. To find out more about lawn mower repair and to ensure the repair professional is suitable for the job, homeowners will want to ask a few key questions before, during, and after the lawn mower repair.
- How many years of experience do you have?
- Can you share a list of references?
- Where do you source replacement parts?
- Are you licensed, bonded, and insured?
- How much will the repair cost?
- How serious is the problem?
- What parts of the mower will you check?
- What is the cost of labor?
- Are the replacement parts intended for this mower?
- Do you use universal replacement parts?
- What is the estimated timeline for completion?
- Do you offer a warranty or guarantee on the work?
- Do you provide a written quote?
- How will additional charges be handled?
- How long will it take to service the lawn mower?
- Is it worth it to repair the mower?
- How frequently should the mower be serviced?
- How can I prevent further issues?
FAQs
It’s not a good idea to rush into a decision when looking for a lawn mower repair company. The homeowner will want to research a pool of potential options and spend some time learning more about lawn mower repair to ensure that the companies offer a fair price for the service. Homeowners can check out the answers below to some of the most frequently asked questions about lawn mowers and lawn mower repair.
Q. Is it worth it to service a lawn mower?
A lawn mower will need to be serviced at least once a year to ensure that the machine is functioning properly and that there aren’t any problems. If the lawn mower is properly maintained, it can last for about 8 to 10 years on average, but if the user neglects the lawn mower maintenance, the machine may give out after only 4 to 5 years of use.
Q. Is it better to repair or replace a lawn mower?
In most cases, it’s more cost-effective to repair the lawn mower, but in some circumstances the user may want to consider investing in a new mower. Homeowners may want to replace the lawn mower if the engine is blown, the transmission needs to be replaced, the current lawn mower is more than 10 years old, or the mower needs frequent repairs.
Q. Are lawn mowers hard to fix?
Whether a repair is easy or difficult depends on the problem. There are many simple issues that fall into the low-end cost range for lawn mower repairs. These issues can often be resolved by a DIYer with a little small-engine repair experience, such as replacing the fuel filter, replacing the air filter, changing the oil, replacing the spark plugs, topping up the fuel, or cleaning the blades. However, for more complicated problems, like a blown head gasket, it’s best for a homeowner to rely on experienced lawn mower repair professionals to resolve the situation.
Q. Is it worth replacing a lawn mower engine?
While carburetor replacement may be worth the investment, replacing the entire lawn mower engine falls into the high-end cost range for lawn mower repairs. Homeowners may end up paying more than 1,000 to replace the lawn mower engine. With this in mind, it’s typically a better choice for a homeowner to invest in a new mower entirely instead of paying to replace the engine.
Q. How many years does a lawn mower last?
When a lawn mower is properly maintained and serviced throughout its life, it will typically last for about 8 to 10 years on average. However, if mower maintenance is rarely kept up, the machine may last only 4 to 5 years before the user needs to start looking for a replacement.
Q. What can damage a lawn mower?
Complex machines like lawn mowers can be affected by a variety of issues. Some problems that can cause damage to a lawn mower include using the mower with a clogged air or fuel filter, allowing rusting, not taking care of corrosion, or even neglecting to add a fuel stabilizer, leading to damaging engine build-up. Similarly, the lawn mower can develop issues if the user doesn’t regularly maintain the mower and fix issues when they occur, or if they install unreliable components, like universal replacement parts or aftermarket engines from box hardware stores.
Q. How often should I service my mower?
The frequency with which the lawn mower should be serviced depends on how often the lawn mower is used throughout the year. At a minimum, it’s recommended that a homeowner have any maintenance work or lawn mower repairs completed once a year. However, if the mower is used more than once or twice a week, the user will want to consider increasing the service frequency to about once every 100 hours of use.
Q. What time of year should you service a lawn mower?
Yard-care equipment should be regularly maintained to avoid any potential problems while the mower is in use. Users can service a lawn mower at any time throughout the year, though most lawn mower repair service professionals recommend having the mower serviced at the beginning or at the end of the mowing season.
Q. How often do you need to clean your lawn mower?
The debris that can collect on the underside of the mower will ideally be cleaned out after every use. Similarly, the collection bag or side discharge chute should also be cleaned out after every use. However, the body of the lawn mower needs to be cleaned only about two to three times a year.
Q. How do you diagnose a lawn mower problem?
If you want to know whether investing in professional lawn mower repair is worth it or whether you would be better off purchasing a new machine, it’s important to know how to diagnose lawn mower problems. Start by carefully examining each part of the mower, including the fuel tank, fuel filter, battery, spark plugs, carburetor, engine, and air filters. Look for signs of damage, excessive wear, corrosion, or contamination.
Also check that there is enough oil and that the mower is set high enough for the lawn. Additionally, you will want to frequently clean out any debris from the underside of the mower to keep the machine operating efficiently.
Q. How do I know if my lawn mower engine is blown?
There are several signs that can indicate that a lawn mower engine is blown, including oil leaks, smoke coming from the exhaust, low fuel pressure, and low power operation. If you still aren’t sure, a lawn mower service technician can confirm the condition of the machine.
Q. How long will a lawn mower run on a tank of gas?
The runtime of the lawn mower depends on several factors, including the type of lawn mower, type of terrain, fuel tank capacity, and engine efficiency. On average, users can expect a riding mower to last between 1 and 3 hours on a single tank of gas. A standard push mower with a gas engine may last 1 to 2 hours, though self-propelled mowers can have a shorter runtime due to the additional expenditure of fuel to drive the mower forward.
How to Remove the Lawnmower Crankshaft From an Engine
Lawnmower crankshafts can get bent from the blade hitting a solid object while mowing, such as a tree root or rock. A crooked crankshaft can occasionally be straightened by heating and bending in a vice, but a severely bent shaft might have to be replaced. The connecting rod pin on the crankshaft will eventually wear enough to require a replacement crank after years of use.
The shaft is cast as one piece of steel, and much of the engine must be disassembled to get it out. Lawnmower engines in the 3 to 6-HP range require very similar procedures for crankshaft removal.
Remove engine fluids
Place a drain pan next to the lawnmower. Tilt the mower enough to gain access to the oil drain plug, and unscrew it with a socket wrench. Drain the oil from the lawnmower engine.
Use a pair of pliers to compress the fuel hose clamp where it attaches to the fuel tank. Remove the fuel hose from the gas tank and drain all of the gas out. Remove the gas cap and turn the mower on its side for an alternate drain method.
Remove the air filter housing, fuel tank or fuel tank/carburetor assembly.
Remove engine attachments
Use a Phillips-head or flat-blade screwdriver to unhook the throttle cable and engine cut-off cables, if so equipped.
Remove the oil tube dipstick, if so equipped.
Remove the pull-start cowl; on electric start models, remove the metal shroud which is bolted on the top of the engine.
Disconnect the spark plug wire. Remove the ignition module or magneto and remove the spark plug.
Remove flywheel
Tap the round starter clutch (if so equipped) moderately with a rubber hammer in a counterclockwise direction to unscrew it from the crankshaft. Take the clutch off.
Unbolt the flywheel. Use a cheater bar or piece of wood to stabilize the flywheel while loosening the bolt. Be careful to not break any of the cooling fins.
Pry under the flywheel with a large flat-blade screwdriver while tapping on the crankshaft end with a rubber hammer. Use a flywheel puller if it still won’t break free. Remove the flywheel. Take out the shear pin from the crankshaft slot.
Remove engine
Turn the lawnmower on its side.
Wear work gloves, and grasp the blade along an un-sharpened section. Hold the blade firmly while rotating the blade bolt with a large wrench to loosen. Remove the bolt and blade.
Turn the mower upright. Locate the engine mount bolts which hold the engine and deck together.
Remove the bolts and the engine from the mower. Place the engine on a workbench for a more comfortable work space.
Remove Valve Spring
Remove the two small screws holding the valve cover in place and take off the cover.
Clamp the valve spring compressor tool onto the top of the spring on one end and between the metal washer and the spring end on the other. Compress the spring.
Jiggle the metal washer until it slides off through the notch on its edge. Remove the washer and slowly release the spring. Do not remove the spring from the chamber. Repeat this process with the other spring.
Remove Crankshaft
Remove the lower engine case on the blade side of the engine. Slide the cover off gently—oil may run out as you take off the cover.
Grasp the camshaft gear and pull it free. Remove it.
Bend the retaining tabs downward from around the connecting rod end cap bolts. Unscrew the bolts and take off the rod end cap.
Press the connecting rod upward so the piston slides to the top of the cylinder. Turn the crankshaft until the connecting rod pin points away from the cylinder.
Slide the crankshaft toward you and remove it from the engine.
Wash the engine exterior with engine cleaner and a spray nozzle before beginning. Place a large piece of cardboard underneath and around the work area.

Wait until the engine is cool before attempting this procedure. Keep your head away from the flywheel when breaking it free—it may suddenly snap upward. Use work gloves when removing the camshaft—the gear is rather sharp.
How to tell if lawn mower crankshaft is bent? Common symptoms with solutions
While using the lawnmower, you will face some problems with this machine. In the previous article, we mentioned fixing plastic gas tanks in the lawn mower.
Today, we will talk about a new issue that is lawn mower crankshaft. If you’ve used a mower, you may have had this problem. And many users don’t know how to fix it.
The crankshaft can cause terrible accidents for you, so you have to learn about it. But how to tell if lawn mower crankshaft is bent? Keep in mind in the article below and we will tell you all about it.
Where does a bent crankshaft come from?
As you know, the blade of your lawnmower always rotates at very high rpm. Some mowers have an rpm of around, but it can reach 3000rpm/around or more. With that speed, when the crankshaft hits an immovable obstacle, it can be bent.
An immovable obstacle can be a fence, a rock, a sprinkler, or something more. When your lawnmower hits one of them while the engine is still running, 100% it will be bent.
During maintenance and repair, the crankshaft was installed incorrectly as another reason for the bent crankshaft. You can complain to the repair facility or the place where you guarantee the product. I’m sure they will repair it for you or completely replace the crankshaft.

Please pay a little attention to the machine during operation to find out what causes the bent crankshaft. It can help you avoid many bad problems after.
How to tell if the lawn mower crankshaft is bent?
Typical symptoms of a bent lawnmower crankshaft
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Excessive vibrations
The first symptom is excessive vibrations. During operation, the machine produces abnormal vibrations continuously and especially makes loud noises. Those are obvious signs of a bent or broken elbow. These symptoms only occur when the crankshaft part of the machine has been bent or broken.
The transmission
The second symptom is related to the transmission. This is quite an important issue. For a machine to work properly, all the parts of the machine need to work well and smoothly. The damaged crankshaft of the machine will cause collisions with other parts, making the transmission system inoperable. If this happens, you will meet a lot of difficulty in starting and operating the machine.
Physically inspect for a bent crankshaft
A physical inspection of the lawnmower is very important. We need to know the situation of the machine when the symptoms begin to appear before they become too serious.
The GAP between the Crankshaft and the Deck
The first thing that comes to mind when doing a physical inspection of a lawnmower is a broken crankshaft. That is to check the clearance between the crankshaft and the deck. If the clearance changes as you rotate continuously, your crankshaft is bent and needs repair. When performing this method, always remember to disconnect the spark plug first.
Look for Bolt Wobble
With this method, we will first disconnect the spark plug. Then have someone pull the cord to start the lawn mower. Meanwhile, watch the bolt that holds the blade to the crankshaft if any movement or wobbling means the crankshaft is bent and in need of repair.
Use a Dial Indicator
The dial indicator is an instrument with a dial that measures or detects minimal changes in distance and amplification that can be observed by anyone. At the same time, we can also use it to check if the elbow is bent or not. We just need to place the dial indicator at a specific point on the elbow and we will get what we want.
Look for blade wobble
Just like the swinging bolt of the crankshaft is bent, so the swinging saw blade is also a harbinger of the bent of the crankshaft. To see the blade, let the machine start on flat terrain. Watch it carefully if it is shaken it could be due to a broken blade but do not rule out the possibility that the crankshaft of the machine is bent.
Watch this video to learn more about “How to know if the lawn mower crankshaft is bent?”:
How to fix a bent crankshaft?
Damage to the crankshaft is one of the serious problems that must be overcome if the machine is to function normally again. Here are some solutions to fix this problem.
Using the Shaft Straighteners
In this method, we will use a straightener to straighten the bent shaft. We will use mechanical force to act on the shaft in a required position. Can be applied in both hot and cold shafts. This is an extremely effective method to return the shaft to its original state to keep the machine working properly.
Sledgehammers
This method is more basic and easier than using shaft straighteners but the efficiency is not as high. The only difference between these two methods is that when using a hammer we will apply a direct force on the crankshaft and when using a shaft straightener we will apply a direct force on the shaft.
Replacing a Bent Shaft
In cases where the elbow is too bent to be repaired as it was, this is the last resort. Do not try too hard to repair this part of the machine as it can easily lead to damage to other parts of the machine. When replacing a new shaft make sure the shaft is suitable for your lawnmower motor.
Check How to fix a bent crankshaft on YouTube:
Final thoughts
The bent crankshaft can cause terrible accidents for users. The most common disasters are foot abrasions, scratches, and worse, the loss of toes, half a foot,… To avoid these cases, please pay attention to your mower even if it’s just a small change. The visible signs are unusual noises from the machine.
Although there are some problems during use, the lawnmower usually is an incredibly useful machine. It can help make your landscapes more beautiful. Using these devices is not hard. But it’s vital to recognize any sign as soon as possible.
Please use the mower carefully for the best results. Hope today’s article helps you know: How to tell if lawn mower crankshaft is bent? Have a nice day!
How to Tell If Lawn Mower Crankshaft is Bent?
Trusted Source Lawn mower. Wikipedia A lawn mower (also known as mower, grass cutter or lawnmower) is a machine utilizing one or more revolving blades to cut a grass surface to an even height. en.wikipedia.org
? You might have recently hit a bump or a rock, and it caused damage to the machine. That might have led to a bent crankshaft, which is a common issue with lawnmowers. The problem is that you have no idea how to fix it.
Before you resort to repairing the unit, it’s important to determine the issue. But how to tell if the lawnmower crankshaft is bent? That’s what we are trying to discover in this article.
You might suspect something is wrong because your machine doesn’t act the same as before. For example, it might be vibrating while starting or during an operation, or you hear loud noises. The problem is that a bent crankshaft can lead to a variety of issues that could destroy your machine but also cause injuries. Here is what you should know about this damage and how to repair it quickly!
Can you find any signs of deformation?
Is there a way to positively identify that a bent crankshaft is causing problems with your machine? You have two approaches to determining the issue. The first one is to look for potential symptoms, and the alternative is to check the crankshaft yourself. Here is a detailed explanation of the lawnmower bent crankshaft symptoms.
Typical symptoms
The problems you can notice come down to the following:
- Unusual sounds and vibrations – it’s normal for lawnmowers to emit some vibration and sounds. The problem is when the sounds are unusual and not the same ones as before. For example, the machine might produce harsh sounds once turned on, but only for a couple of seconds. It might vibrate excessively when you are trying to move it. Anything that seems out of the ordinary can be an indicator of a bent crankshaft.
- Transmission problems – these occur when you try to ignite the lawnmower. It’s similar to starting a car – you might have trouble turning it on, and it could require several tries to succeed. It’s a common symptom of a bent crankshaft.
Physical inspection
The next is a physical inspection, which means checking the crankshaft by yourself. Now, there are multiple ways to do this, and we’ll explain them below.
While you are assessing the unit, you might encounter other issues, too. If you have a problem with your blades, find a replacement among the best lawn mower blades to ensure the maximum longevity of the new component.
How does it work?
If you want to determine a bent crankshaft, it’s best to ask a neighbor or family member to help with assessing the damage. For starters, take off the spark plug from the machine. Now, ask the other person to initiate the cord to start the machine. While they do that, you FOCUS on the blade and the bolt that holds it. If you notice any shakes or wobbles, it’s an indicator something is wrong.
Now, there is another method on how to perform a physical inspection yourself. Here are the steps to follow:
- Remove the spark plug and turn your machine over.
- Identify the cutting deck skirt on one end. Use a ruler and clamp it from the deck’s edge to the place where the shaft touches it.
- Use your hands to turn the shaft. Check out the gap and see what happens during a single rotation. Did it expand and contract after that? If that’s the case, there’s a deformity in your crankshaft.
To avoid these issues in the future, you can also get an electric model, such as the Greenworks G-MAX 25322. It can mow 400m2 on a single charge and is suitable for various grass types.
What causes a bent crankshaft?
Your mower’s blade operates at over 200mph when in action. Those are huge speeds, which is why the machine uses plenty of kinetic energy. Once the unit encounters an obstacle, such as a blade, it dissipates energy through the shaft and the blade. It’s that energy that causes the bending.
Here are some causes of a bent crankshaft:
- You hit a rock, sprinkler, pipe, or another immovable object that’s not too light.
- You tried to do something with the machine and dropped the shaft accidentally.
- Something went wrong during the manufacturing, installation, or maintenance process.
It’s always Smart to pick reliable and high-quality mowers to reduce the risk of any issues. The selection of the best corded electric lawn mowers can help to identify the right machine in that category.
How can I repair a bent crankshaft?
The first thing is to secure the right tools.
Here is what you’ll require:
- Wrench
- Screwdriver
- Nut drivers (depends on the machine)
- Socket set
- Heavy pipe
- Valve spring compressor tool
- Rubber hammers
- Vise grips
The first step is assessing the shaft. Here are the steps for doing that:
- Make sure your lawnmower is cool and turned off. Make sure to drain the oil by removing the oil plug. Now, drain the fuel by disconnecting the hose and opening the gas cap.
- Remove the air filter and then take off the engine. You want to remove the oil tubes and throttle cables, too.
- Now, take off the clutch, but use a wooden piece to place between the housing and the flywheel.
- Pry loose the flywheel bolt and remove the shear pin from the shaft. Remove the bolt from the blade, too, and take off the bolts that hold the engine and the deck.
- Place the motor in a safe position and use a screwdriver for the screws that keep the valve spring cover. Use the compressor tool to push down the spring. Allow it to compress and then slowly let go. Now, do the same with the other valve.
- Check out the blade and find the camshaft gear. Remove it and unscrew the bolts to access and disconnect the rod end cap.
- Slowly turn the crankshaft and take it off the engine.
Now, let’s do the straightening process. Position the shaft on a solid surface and place a heavy pipe on top of the bent. Use a hammer over the pipe several times. Now, see if the shaft is straight by using a level. If necessary, do some more straightening with the pipe and the hammer.
Once everything is straight again, assemble the machine back. You can follow the same steps above but in reverse. If you did everything right, the machine should work correctly again.
Trusted Source Buying a lawnmower: a guide | Family finances | The Guardian Whatever the size of your green sward, it’s time to consider how you are going to keep it under control. www.theguardian.com
? Check the CRAFTSMAN M105 lawnmower, an affordable battery-powered unit that’s an excellent choice for residential landscapes. The maneuvering process is easy with the bigger rear wheels, and you can pick from five different cutting heights.
Extra tips
Here are some other crucial things to note when dealing with a damaged crankshaft:
- Check the warranty – is your product still under warranty? If the answer is yes, you’ll need to find a licensed technician. If you try to repair the issue yourself, it will void the warranty. If it happens that you fail during the repair, you will have to pay someone to fix the unit.
- Is the repair worth it? – although fixing a bent crankshaft doesn’t have to be expensive, replacing this part is. If the replacement is necessary, make sure that’s the right move. Perhaps it’s better to check out the best lawn mowers under 400 and invest in a new unit.
- Pay attention while mowing – the reason why the crankshaft gets bent is that it hits an obstacle. It’s impossible to notice every rock, but paying attention while mowing might decrease the risk of bending it.
FAQ
Q: What’s the price of replacing a bent crankshaft?
A: The total price shouldn’t go over 100. If you decide to pay a professional to handle the repair, that could increase the cost to 150.
Q: Is it possible to continue using the lawnmower when the crankshaft is bent?
A: While it might theoretically be possible to use the machine, the experts advise stopping immediately. If you notice any issue with the crankshaft, it’s imperative to stop it from damaging the engine and destroying the unit. It’s easier and more affordable to fix a bent crankshaft than a damaged engine.
Q: Is it Smart to fix a bent crankshaft by yourself?
A: You should only do this if you know what you’re doing. If you are unsure about any step of the process, call a professional. It helps if they are a licensed agent for that mower brand. Another thing to consider is the warranty – if it’s active, you shouldn’t handle the repair yourself.
Final thoughts
A lawnmower is an incredibly useful machine. It makes maintaining residential and commercial landscapes easy. While using these devices isn’t challenging, it’s vital to recognize any problem as soon as it appears. A bent crankshaft is a common issue with mowers, so pay attention and make sure to recognize the signs.
We hope our guide helped with how to tell if the lawnmower crankshaft is bent. You should rely on your eyes and ears when determining the issue. Once you establish the bending of the crankshaft, you have the option to repair it yourself. However, make sure that you know what you are doing during each step. You don’t want to risk causing even bigger damage. If you feel like you could use help, don’t hesitate to contact a professional.
References
A lawn mower (also known as mower, grass cutter or lawnmower) is a machine utilizing one or more revolving blades to cut a grass surface to an even height.
Whatever the size of your green sward, it’s time to consider how you are going to keep it under control.