Surging Kawasaki Engine
I have a 15hp Kawasaki on a 48 Lesco and the engine surges. I did all the routine things I could think of. Changed oil, air filter, emptied carb bowl, cleaned fins, sprayed carb cleaner, fuel filter. A couple of times it stopped surging when bring it to full throttle. Anyone have any Ideas?
you need to remove the carb and clean it. you need to clean all the jets. Surging is caused from a lack of fuel.
Michael Martinez
i would put my paycheck it is in the carb. 99.9% of the time surging is caused from lack of fuel. take the carb off and take your time cleaning the jets (all of them) Dont just spray carb cleaner into them. sometimes you will need certain tip screwdriver sizes to get the jets out. just take your time cleaning with carb cleaner and blow the jets and carb out with air. i am sure this will take care of the problem. make sure all gaskets are in good shape. (do not use silcone for gaskets) let me know.
I would tend to agree that you have a carb obstruction. After my experience with two Kaws(17 and 23 twins) do not overlook worn governor internal parts wear. In one case the plastic plate that separate the governor balls had badly worn bosses on the back as well as a badly grooved governor plate. In the other case, the bosses had been sheared off causing the engine to over rev. In the latter case, prior to over reving, the customer experience the surging you describe. Just something you may want to consider if the carb cleaning doesn’t correct the problem. It would also depend on the number of hours you have on the unit and whether or not you had ever esperienced any low oil situations.
Michael Martinez
the unit is abouty 8 years old and it is a workhorse. Yes it has expierenced low oil sits. I’ve never cleanded jets or repaired governors how hard are govenors to work on?
If cleaning the carb as leeker and Dutch mentioned (which I also think so) does not solve the problem check the governor adjustment.
“Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride”.
dutch1
Clean up the carb first and that could solve your problem. If not, obtain your model and code then proceed to Kaws website to get a parts breakdown to see what you face as far as parts and orientation. If you don’t open up engines on a regular basis you should obtain a repair manual for your model.
Before you take anything apart. Pop off the discharge side of the fuel pump line, get a small can, start the motor and see how much fuel you are pumping. And do this while the tank is very low. Only takes a few seconds to see flow and shut the unit down. Do process of elimination in order that way you wont over look a step. Start at the gas tank and go from there.
How to Fix Surging Lawn Mower
Do you have a mower that surges when it’s running? There are many possible reasons for this, but most of them can be fixed with some simple adjustments. To restore the problem, you need to make sure your blades are in good shape and clean; they should be sharpened regularly. You’ll also want to check how tight the blade bolt is on your mowing deck (it needs to be adequately tightened!) And if none of these things work, then chances are it might just be time for a new lawnmower! In this blog post, we will cover how to fix surging lawn mower so that you can make it quick work out of cutting grass and getting rid of weeds without all that bending over.
Dirty Air Filter:
This is the most common reason for a lawnmower that surges. If your lawnmower is equipped with an air filter, you should clean or replace it often, depending on how often you use your mower. A dirty air filter will cause the engine to work harder, increasing fuel usage and producing more emissions.
Obstructed Carburetor:
If your lawnmower suffers from the symptoms of surging, it may be a result of a dirty or clogged fuel line
Dirty/clogged Spark Plug:
If your engine is not firing on all cylinders, it may be due to a dirty spark plug. This can also increase fuel usage and prevent proper combustion. A clean spark plug is essential for optimum engine performance and fuel efficiency.
Clogged Air Filter:
A clogged air filter restricts airflow and increases your engine’s workload. Clean or replace your air filter as needed to prevent this issue from occurring.
Incorrect Fuel/oil Ratio:
If your lawnmower is not getting the correct amount of oil, you will use excess fuel, and this will cause it to surge. Make sure that you check your owner’s manual for proper engine oil dosage.
Overheating:
Your lawnmower will surge if your engine is overheated due to a lack of water or overheating. This is because an overheated engine reduces its power output, which causes it to work harder.
Dirty Muffler:
If your lawnmower is equipped with a muffler, check if it’s clean or replaces it as needed. A dirty muffler will create excess heat, and this will cause your engine to work harder and surge.
Incorrectly Gapped Spark Plug:
A spark plug with an incorrect gap will cause your engine to surge and increase fuel consumption. Make sure that you check your owner’s manual for the recommended gap of your mower.
Leaking Oil:
If there is a leak in the crankcase, it could be caused by a worn-out piston ring. Also, if your mower has an oil-drip hole, make sure that it’s clean and free of debris.
Engine Speed Too Low:
If the engine speed matches the speed of your lawnmower, it will cause your mower to surge. This is because if you exceed its limits, the engine cannot handle the extra work, and this causes it to work harder. So, for example, if your mower’s max engine rpm is 3600rpm and you are running at 1800, it will cause it to surge. You Can Check It Out to Install Side Discharge on Lawn Mower
Methods on How to Fix Surging Lawn Mower:
Clean Air Filter:
If your lawnmower has an air filter, you can clean or replace it as needed. However, if it’s dirty, which is the most common reason for a mower that surges, your engine will work harder and faster than it needs to. This will cause it to surge and can shorten the life of your mower’s engine, so clean or replace as often as necessary.
Check Spark Plug:
If the spark plug is dirty or damaged, it can affect how well your mower starts and runs. Clean the plug using a wire brush and feel to see if it’s hot. If so, an air leak may be caused by damage or poor connection. Next, look around the base of your lawnmower to find where you can access and tighten or replace the spark plug. If the air leak is small, you may be able to pull it yourself. If not, you’ll need to take it in for service.
Change the Oil:
If your mower isn’t running on clean oil, your engine will work harder, so change or clean it often. Check your owner’s manual to find the right amount for your lawnmower. Remove the dipstick, wipe it on some newspaper to dry it off, and then replace it. Pull it back out and look at how many inches of oil are present in your mower’s engine. If you don’t have enough oil, add more before restarting.
Add Fuel Stabilizer:
Stabilizing your lawnmower’s fuel before storage will keep it from deteriorating. This is better than just running the mower until it runs out of gas because that could leave you with a carburetor full of stale gas that won’t run properly when you restart in warmer weather. So instead, add a stabilizer to the mower’s fuel tank and allow it to run until the engine stops.
Replace Fuel Filter:
If the fuel filter is dirty, it could also cause surging. It should only need to be replaced every few years or so, but you can return it whenever you use a stabilizer in your mower’s gas tank. If a fuel filter is clogged and isn’t being cleaned regularly, it will allow particles into your engine that can damage it and even break it.
Check and Tighten Bolts:
A lawnmower that surges can also result from a loose part, like a bolt or hose clamp. You’ll need to check your owner’s manual for where you can access all of these parts, as not all models are built alike. Tighten as required and check for signs of damage. If the piece is damaged, replace it with a new one from your lawn mower’s manufacturer.
How Do You Stop a Lawn Mower From Surging?
If you’re experiencing surging with your lawn mower, there are several steps you can take to solve the problem. Start by cleaning or replacing the air filter. A dirty air filter can prevent the engine from getting enough air, which can cause it to surge. It’s also important to check the fuel system for clogs in the fuel filter or fuel line, as this can also cause surging. If the fuel system is clean, you may need to adjust the carburetor to the manufacturer’s specifications. Finally, check the spark plug and inspect the blade. A damaged or unbalanced blade can cause surging, while an old or dirty spark plug can also be at fault. Following these steps, you can stop your lawn mower from surging and return to a smooth mowing experience.
This article is going to cover how to fix a surging lawn mower. It has also provided helpful information on what causes the problem and ways of solving it. Surging occurs when the engine speed fluctuates widely, often as much as 1,000 rpm at times or more than 5% from its average running rate. The oscillations are usually caused by one cylinder firing before another fully completes its cycle. All of the information in this blog should have helped you understand how to troubleshoot your lawnmower. If not, let us know, and we’ll be happy to help!
How to Stop your Mower’s Engine from Surging
When the engine in your Cub Cadet can’t hold a steady speed, it can be difficult or impossible to use. Fortunately, while there are several possible causes that can result in surging, these are easy to identify and remedy. Here’s what you need to look at to get your equipment to run like it should.
What is Surging?
Surging happens when the engine isn’t getting enough fuel or air to run at full speed, but it can still get enough to run at a lower speed. When air and fuel are limited, the engine speed drops, it runs better, and then it accelerates until it hits this limit again. This causes a cycle of fluctuating engine speeds which makes it difficult and sometimes dangerous to operate equipment. Fixing this problem requires inspecting and remedying problems across the entire intake including the fuel system, filter, carburetor, and governor.
A dirty filter can keep the engine from drawing in the air it needs to run at full speed, but still provide enough air at lower RPM.
Paper filters can be cleaned by tapping them against a hard surface to knock free any loose dirt. Foam filters can be cleaned in water and a mild detergent or with a non-flammable solvent. After cleaning, the foam needs to be soaked in clean motor oil and any excess oil should be squeezed out before reinstalling. Paper filters should be replaced if they’re saturated with dirt and all filters should be replaced if they are damaged. When cleaning the filters, remember to wipe out the filter housing and make sure it hasn’t been damaged, which can let the filter flex under load and restrict airflow.
Fuel System Problems
As gas leaves the fuel tank, air is needed to replace it. This air enters through small holes in the gas cap. If those holes are clogged, the pressure inside the tank will drop, keeping the fuel from being drawn through the fuel line.
Lines and filters should be inspected for clogs and cracks to ensure the fuel leaving the tank makes it to the carburetor.
If you have old fuel, it may not want to burn. As a general rule, when powering a four stroke engine, gasoline should be used within one month of purchase, and within three months if it has been mixed with a fuel treatment. Fuel injected engines can usually run on older gas, while two-stroke engines are much more sensitive to stale fuel. Carburetor jets can clog if dirty or old fuel passes through them, particularly ethanol-free fuel, which will gum up as it ages. Fuel containing ethanol is less likely to turn sticky, but it will draw water from the surrounding air, making it harder to burn. In either case, the old fuel should be drained and replaced with fresh fuel.
Vacuum leaks
As the piston moves down during the intake stroke, that space expands, drawing air through the filter and mixing it with fuel from the carburetor or injector before it enters the combustion chamber. However, if there are any leaks, the engine can draw in outside air that hasn’t had fuel added to it, leaning out the mixture.
Start by tightening all the bolts around the carburetor: these can work loose after being subjected to engine vibration, letting the carburetor separate from the head. If the engine is still surging, inspect the gaskets between the carburetor and the head to ensure they’re creating a tight seal.
Lawn mower engine surging
At idle the engine in my 2 year old Honda powered mover is surging something fierce. When I engage the blade, it still does it but not as much. I have stuck my fingers into the levers and cables to rev it up a bit, but I can tell it’s still surging.
It’s got plenty of oil and the air filter is clean.
How do I fix this myself? I don’t want to take it to the shop. The grass will be to my ass by the time I g et it back.
I would say Italian tune up. Use it, it will either get better or worse. Either way you’ll have done your part.
disconnect the govenor. you should see a bar moving back and forth opening the throttle blade when its about to die, and closing it as it revs. you can disconnect it and maybe run a throttle controll from a local hardware store. this is how BS motors work, pretty sure the Honda is similar
This happened to my lawn mower a couple months ago. I ended up taking it to a shop and they rebuilt the carb for about 60. Now it works like a champ. They blamed the problem on inactivity. I hadn’t used the mower in about a year. They said even if you don’t mow your lawn, you should still start it monthly to keep things in check.
Throw a new spark plug in it first. I even went a step hotter since it was burning so rich.
If that doesn’t work, try rebuilding the carb. There aren’t many parts. You can probably do it without parts or a manual.
Same problem with my Poulain about 2 years ago. Checked spark plug and governor and both were fine. Did a “rebuilt” of the carburetor and that solved the problem completely. The kits are available from the local hardware store (Lowe’s for me). In my case it was just a rubber membrane with some holes cut out of it. Removed 4 screws to split the carburetor horizontally and replaced the rubber piece, while keeping track of which loose pieces were above and which ones were supposed to be below the membrane. Hopes this works for you too.
While reading up on this on the internet before my fix, I read a warning not to run it while it is surging. The surging is caused by the mixture being way too rich and that can wash the oil from the cylinder and do permanent damage to the engine.
Harold 89 911 Targa, 96 Saab 900S, 02 Passat 1.8T Wagon 02 BMW 530i, 08 Cayman, 17 GTI DSG 19 Subaru Forester
I hadn’t thought about the washing the cylinder wall issue. Guess it’s time to rebuild the carb in addition to the plug.
I say clean out the carb. Used to have this same problem on a Briggs, it would need the occasonal cleanng
The carb is probably plugged up a bit, which causes the engine to run lean, which causes the the engine speed to fall off, and the governor forces the carb to open more, thus the surge cycle begins.
Solution? Clean/rebuild the carb, or buy a new one. If you’ll reply with the frame and engine serial numbers, I can get you a price on a new carb. For many Honda mowers, the carbs are cheap enough to simply replace, and easy, bolt-on job.
I’ve got five kids, an Italian wife, and I (used to) write about lawn mowers. You think you have problems?
Try removing the float bowl and cleaning the jets, before going to the trouble of rebuilding the carb. I had a Honda a few years back and had to clean the crap out of the bowl frequently. No fuel filter and a poor tank venting system ensured a constant addition of crap to my fuel.
Sold it and bought a John Deere and never looked back.
Sold it and bought a John Deere and never looked back.
Honda engine here, on a commercial grade walk behind snapper. I installed an inline motorcycle filter. I’ve noticed the float bowl has a drain plug, but never had to use it. I also turn off the fuel to the carb after every mowing, let the carb run dry. So far, so good. no problems. Contaminated fuel in the float can cause problems.
“Now, to put a water-cooled engine in the rear and to have a radiator in the front, that’s not very intelligent.”.Ferry Porsche (PANO, Oct. ’73) (I, Paul D. have loved this quote since 1973. It will remain as long as I post here.)
Why Is My John Deere Engine Surging? (Answered)
To say that the Deere brand is “iconic” would be the understatement of the year… and how. The company’s stellar reputation is built on delivering capable machines that seldom let you down. Deer mowers tend to adhere to this 184-year tradition of excellence, but they are not always infallible.
John Deere engine surging is a sign of some element of the fuel delivery system either being restricted or clogged. Areas to check for a solution to the problem include: gas caps, filters, fuel lines, and spark plugs. Either regular cleanout or replacement is advised.
Today’s article focuses on an all-too-common problem: engine surging. What is it? What causes it? importantly…what are the possible solutions?
Well, stick around and find out.
Signs And Causes Of A John Deere Mower Engine Surging
It’s a lovely Saturday morning and, as usual, you bring out your trusty Deere for your weekly lawn touch-up. Only this time, the mower’s motor RPM yo-yos up and down, regardless of how hard you push the accelerator. It revs at its maximum one moment, then seemingly runs out of steam the next.
The engine doesn’t completely peter out, but this occurrence is weird…and understandably concerning. After all, these machines cost a pretty penny.
In such a scenario, chances are your lawnmower (or, more specifically, its engine) is experiencing what is known as an engine surge.
This unpredictable RPM fluctuation is the classic sign of this problem. It is an issue that can occur during acceleration or when the machine is idling. Luckily for you, it is not all that rare.
John Deere engine surging is a result of an inconsistent combustion process in the engine cylinder(s). specifically, it is caused by inconsistent delivery of fuel and/or oxygen to the combustion chamber. The usual problems lie in the air filter, gas cap, fuel lines, or carburetor.
As you know, for an engine to fire and produce power, it needs a combination of fuel, air, and a spark from a sparkplug to produce an explosion known as combustion.
To facilitate this process, a lawnmower has a fuel delivery system (fuel tank, fuel lines, fuel filters, carburetor, etc.) and an air delivery system (vents, air filters, air inlet valves, etc.). These delivery systems and your sparkplugs must be in tip-top shape and free from blockages at all times.
Therefore, if your mower is surging, there are a few ports of call.
Clogged Air Filters Can Cause Engine Surge
First, we recommend that you inspect the air filter. As the name suggests, this component is there to protect the engine from dust and debris that may be in the air. When working normally, the filter blocks these particulates and ensures clean air is delivered to the sensitive parts of the engine.
Over time, the build-up of dust and debris slows down the rate of this clean air delivery. Eventually, air (oxygen) won’t reach the combustion chamber at all or when it’s needed, resulting in inconsistent power output.
Slow Fuel Delivery Systems And John Deere Engines
The second thing you want to inspect is your fuel delivery system.
The Gas Cap
We recommend you start with simple things like your gas tank cap. These caps typically feature a small hole on the inner side. This hole is a clever piece of engineering that facilitates the creation of backpressure in the tank. This pressure helps push fuel into the fuel lines towards the carburetor.
Unfortunately, the small size of these holes makes them susceptible to blockages from dust or oils. Always check this first before completely disassembling your fuel system.
Fuel Lines
If the cap hole is not the issue, you should move on to the fuel filter and fuel lines. The filter is prone to debris blockages, especially if you use low-octane gasoline. Naturally, blockages result in inconsistent fuel delivery…which can cause surging.
Fuel lines are narrow tubes that deliver fuel directly to the carburetor. They are typically made of plastic and they are often transparent or semi-transparent, which makes it easy to spot blockages.
Carburetor
Next, we have the carburetor. This vital component has the delicate role of “spoon-feeding” fuel and oxygen directly into the combustion chamber. Delicate is an apt description for the carburetor, as even the smallest bits of gunk and debris can disrupt its functioning.
The carburetor is made up of a bowl, a float, and several valves. Dirt can negatively affect a bowl’s fuel carrying capacity and the movement of the float. Dirt can also block the inlet/outlet valves (commonly known as “needle valves” due to their small sizes). Regardless of the particular disruption, engine surging may be the result.
The carburetor is also prone to air and vacuum leaks when it is loosely attached to the engine block. This results in excess air flowing into the combustion chamber, which disrupts the delicate fuel/air mix necessary for efficient combustion.
Even worse, a vacuum leak will negate the backpressure required to suck fuel towards the engine efficiently. Again, the fuel/air mix will be thrown out of whack.
Since many lawn mowers and tractors today are sporting Kawasaki engines, here is another article you may be interested in… Kawasaki Engine Problems: Diagnoses, Fixes, And Tips
How To Fix A Surging John Deere Lawn Tractor Engine?
Now that we’ve identified some of the problems behind a surging mower engine, let’s talk about some of the solutions you can opt for. There are two main actions you can take for any of the problems that could arise.
To fix a surging John Deere mower engine the problem must be diagnosed and then the component either cleaned out or replaced. With parts like filters and spark plugs, replacement is the best option. Oil should also be replaced on a regular basis. Carburetors can be cleaned or replaced.
Let’s take a look at some of these specifically…
Regular Service And Maintenance
The first (and highly recommended) thing to do is ensure the machine is serviced. This involves oil changes, sparkplug replacement, and air filter replacement. Foam air filters can also be cleaned using soap and water. Paper filters must be replaced.
Luckily, Deere mowers have specific service schedules that serve as a guideline for what needs to be done at specific milestones. These guides are provided by the manufacturer and are often attached to the back (or bottom) of the operator chair.
Oil Change
Oil changes are important for the smooth movement of the engine piston and other moving components. Deere usually recommends oil changes after about 50 hours of use.
Spark Plug Changing
This is usually an easy task for most John Deere machine owners. The difficulty for most will be knowing which spark plug to replace it with.
Spark plugs are not one size fits all or even one size fits most. Many brands formulate their own size and capacity of spark plug to fit their particular machines.
For more on how spark plugs work in mowers like John Deere and other major brands, I have an article that deals specifically with them. See Are All Lawn Mower Spark Plugs The Same?
Air Filter Replacement
Air filters are an important safeguard for keeping debris out of engine lines and cyclindars. These are most often an inexpensive way to cure some seemingly major problems.
Simply changing the air filter can dramatically improve the workings of a John Deere mower. These engines are built to run well and last. Yet, even these quality machines are reliant on clean air and fuel to operate.
Regular air filter replacement can stave off problems like engine surge.
To read more on mower air filters, see my article dedicated to just that… How Often Should You Change A Mower Air Filter?
Carburetor Issues
If you are certain that service isn’t the issue, you will have to look at the carburetor, which is often the prime suspect in this case.
Most people are better off taking the mower to a repair shop. However, if you are confident, you can get in there yourself and have a look.
If the carburetor is the problem, you must take it out, take it apart and clean it.
We highly recommend a visit to Amazon for a carburetor cleaning kit with brushes and needles that you can use to push out gunk and debris. You should also dip the carburetor components in a carburetor cleaning agent to dissolve any particulates.
Finally, you must also inspect the bolts securing the carburetor to the engine block. Tighten any loose bolts you find to reduce air leaks and maintain vacuum pressure. Any worn-out gaskets between the carburetor, manifold, or engine must be replaced as these can facilitate leaks.
The Final Touches On Surging John Deere Engines…
Though John Deere is one of the leading names and manufacturers when it comes to quality lawn care products, even their engines as they rack up mowing hours can run into issues due to clogging or deferred maintenance.
Even with regular maintenance, sometimes parts will need to be either cleaned or replaced.
Mathew has worked in landscaping professionally for over 10 years. He is a grandpa and frequently interviews other experienced landscapers and lawn care experts who are also grandpas for these articles.
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Frequently Asked Questions About Lawnmowers Surging Losing Power
How often should I change the oil in my lawnmower?
You should aim to change the oil inside your lawnmower after every 50 hours of use, for some people this could be sooner or later, so it comes down to personal judgement too.
Always check the oil to see if it still looks healthy if you are unsure.
Can a faulty spark plug on my lawnmower cause surging issues?
Yes, the spark plug on your mower is essentially what allows the whole mower to start up, so when this plug is broken, it will cause surging issues and can even cut off your lawnmower’s engine during use.
Why is my lawnmower losing power when it’s used uphill?
Low fuel, ignition issues and dirty blade build-ups can be the reasons for engine issues when your lawnmower is operated uphill.
How long will a fuel stabiliser extend the life of my fuel till?
A stabiliser could help extend the regular lifespan of your mower’s fuel from 30 days to a year or even three depending on the brand.
Final Words
To conclude, most of the time your lawnmower will be surging and losing power if there is something from with the gas or airflow in the engine, to find out what the issue is, you can follow our troubleshooting guide above and maintain your lawnmower regularly to avoid dirt-build issues and blockages from happening in your mower’s engine.
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