To understand this problem, you also must know that there are different color smokes that a lawn mower can blow out the exhaust pipe.
Blue smoke is an indication of oil that is burning in the combustion chamber. When you remove the spark plug, it will have an oily and tar looking appearance to it. It can also have a baked on oil shine to it.
Black smoke means that the engine is running rich. Running rich means that the engine is getting an incorrect fuel/air mixture. It is getting more fuel than air and thus burning in a rich condition. A clogged air filter is often the culprit here.
White smoke is normally an extremely rich condition. Sometimes it can be an oil burning issue but in most cases the engine is getting way too much fuel to burn and cannot burn it all thus making the white smoke. Things that can cause this is a carburetor needle and seat leaking and filling the combustion chamber up with fuel. This fuel also gets pumped out of the cylinder and ends up in the exhaust muffler. When the muffler gets hot, it heats up the fuel and produces more white smoke.
Try removing the spark plug and slowly cranking the engine over when the engine has cooled. Be careful as a stream of fuel may come shooting out of the sparkplug hole! You can place a rag over the sparkplug hole to catch the fuel that comes out.
Each lawn mower engine smoke condition has its cause and by knowing what color to look for and the steps to take to correct it, you can cure the my lawn mower is blowing white smoke problem.
Well, it has arrived. The first EFI riding lawn mower has been debuted by Cub Cadet. The XT-1 LT46″ EFI FAB is now at your local big box store such as Home Depot and your local Cub Cadet dealerships.
With a price tag of $1999.00, it is $300 more than it’s carbureted version which is not a lot of money for the performance gains you will receive. Better starting, more power, better throttle response, better fuel economy and you won’t have plugged up carburetor jets to deal with anymore.
EFI or Electronic Fuel Injection has been around since the 1980’s on automobiles and it has finally been installed on the riding mowers. It has been on larger Zero Turn mowers for some time now and will slowly trickle down to the smaller machines such as self-propelled and push mowers in time.
All of this is great, but it also adds a whole new level of complexity to the lawn mower and more expensive parts. When an EFI engine goes down, the days of changing a spark plug to fix it are long gone. In order to troubleshoot it, you must have expensive test cables and software to hook up to the engine harness and read the fault codes and engine data in real time. This software is not available to the general public and at this time is limited to the dealership level. What that means is you will have to take your mower to the dealership or have them come and haul it off for repairs.
Here is the bad news. In the good old days of the carburetor, if the fuel pump was bad and needed replaced, you could get away with a $30 fuel pump plus labor bill and be on your way. With EFI there will be diagnostic time that will be billed, labor and of course parts to replaced. For instance if just the fuel pump goes out on your EFI machine, you are looking at a $200 just for the fuel pump part. EFI parts are expensive compared to a carbureted machine.
And there are also many different parts to an EFI system. You have a computer, an oxygen sensor, fuel pump, fuel injectors, high pressure fuel lines and a variety of sensors on the engine to monitor it’s condition. Again, these are all expensive parts to replace and if one of them goes bad, it affects the entire engine and can easily shut it down.
Fuel Injection is not going away and the more the EPA pushes for more air quality standards on small engines, the faster implementation will roll out. You can still buy many machines with a carburetor on them and that will last for some time but not forever. Parts for carbureted mowers will be available for a good while as well.
The question to consider is this. Do I have the money to pay for an expensive repair on an EFI equipped riding lawn mower or should I buy one with a carburetor and still be able to work on it and not have as expensive repairs if it breaks down?
Then dig in and do your research on these two popular websites:
Popular Mechanics and then enter your mower info in the search area.
And after you do your research and check the reviews, then you can make an informed decision on should I buy a fuel injected or carburetor riding lawn mower.
The first thing you need to start your business is knowledge and information. You must know how to successfully open your business, make money and be profitable at the end of the day. If you have some mechanical skill and are eager to learn how to repair lawn mowers in a business, my recommendation is to buy a book that will get you pointed in the right direction. You could run out and buy $500 worth of tools but if you don’t know how to attract clients, then you are dead in the water from the very start.
After you research how to get your business going and hopefully read this book, you will need to know who the suppliers are that will get you the parts you will need.
Next, list your business on this website with our FREE Trial listing! Click here for more info: FREE BUSINESS LISTING
If this is going to be a hobby or side lawn mower repair business, here are some websites that will help that you can purchase things from without an account.
If you are going into this as a full-time business, then you want to get an account set up with the companies that can support those needs.
These engine manufacturers normally have large distribution companies that move their parts and then those distribution companies may also sell to regional parts supply centers. You want to buy from the Master Distributors when you can.
Briggs & Stratton
There is one main Master Distributors of Briggs and Stratton parts and that is Power Distributors.
Those are the main engines you will see coming into your shop. You will no doubt see others and the Chinese are making many different engines and they are being installed on American lawn mower chassis.
When you need parts and accessories for engines and different machines, these companies can get you quantity discounting on things like air, oil and fuel filters, lawn mower blades, starters and just about anything else you will need. You will want to set up an account with them!
By gaining the right knowledge and training, you will know how to start a lawn mower repair business in your hometown and begin making money doing lawn mower repair on the side or full-time.
This problem requires some critical thought and the process starts with heat. What does heat do to an engine? It makes the fuel hot if the gas tank is located near the engine and it heats up the ignition system. It also affects the choke system if it is not adjusted properly. Heat expands things and this expansion affects the metal tolerances inside an engine.
You may use your mower for 15 or 30 minutes and then shut it down to remove a stick from the yard or refill it with fresh gasoline. You pull the rope or turn the key and nothing…nada.
First, let’s check the choke to be sure it is working like it should. Is it closing and opening normally? If not, this could be the problem.
Second, let’s check for spark and see if you have a good blue spark if you are using the plug to the cylinder head method. An inline spark tester will show a bright orange glow or a bright blue spark depending on the type of tester you have. On occasion once an engine is shutdown and heat soak has begun, it could affect the sparkplug or the ignition coil and not allow good spark to occur.
Third, are the intake and exhaust valves properly adjusted to the specs your engine calls for? Valves that are too tight or too loose will make for a no start when hot.
Lastly, you may have water in your fuel that is making it hard to start. Take a fuel sample at the carburetor to see if you have any water in the fuel or other contaminants.
By checking each one of these items one by one, you can home in on the lawn mower will not start when hot issue.
This is a very common problem. You keep pulling the pull cord until it finally starts or you turn the key and crank and crank until it finally starts. Both result in the same hard starting lawn mower engine.
It comes down to a common few things that cause this problem. One is you are not getting enough fuel in the engine because the fuel pump is going out or there is an obstruction in the line, fuel filter or the carburetor. Try turning the engine over on a riding lawn mower with the fuel line disconnected at the fuel pump outlet line and have a catch can waiting to catch any fuel that comes out. If fuel comes out readily, then your fuel pump is fine.
On a gravity fed system. unhook the fuel line at the carburetor and see if fuel comes out. You will need a tool to pinch the fuel line closed and they make a special one with smooth jaws for this. If you don’t have a way to stop the fuel from flowing, you will have a big mess to clean up!
If fuel is going to the carburetor, then pull the spark plugs and make sure they looks slightly wet with fuel. If they are, the problem is most likely your valves are out of adjustment.
On a push or self-propelled lawn mower, to test for fuel getting to the engine, pull the cord or turn the key on an electric start a few times and then remove the spark plug and see if there is fuel on it. If there is, your valves are probably out of adjustment if it is an overhead valve engine.
Another common item to cause this problem is the choke not set properly or it is malfunctioning. Check to be sure it is closed when you are starting the engine and slowly opening as the engine warms up.
Blown headgaskets can also cause hard starting and low cylinder pressures due to bad piston rings or valves that are not seating well. The carburetor may not be venting either and throwing a lot of fuel into the engine flooding it. The needle and seat may be failing an flooding the engine as well.
Bad fuel or water in the fuel can also cause hard starting in your lawn mower.
Check each system one at a time to help narrow down what the problem is and then find out which specific component is the culprit to solve my lawn mower is hard to start problem.
This is another frequent problem with a lawn mower. It will run for a while and then dies. It could run for a few seconds or it could run for 30 minutes and decide to conk out. It really doesn’t matter to you of course as you want it to keep on running!
A few things you can check is to make sure your fuel is good. Your mower needs clean and fresh fuel to run. If you can take a fuel sample, it should be clear, not have any discoloration other than a slight yellowish color and not have any debris or particles in it. The odor should be strong and not stale.
If you determine that your gas is bad, it will need to be removed from the carburetor and the fuel tank and fresh fuel added.
Another problem is a carburetor that is plugged up. It will run on choke but when it transitions to the main jet, it will stumble and die because it is not getting fuel through that jet. Cleaning the carburetor is the solution for this problem.
Your choke could be stuck closed and cause the mower to run for a short period of time and then die. You can tell this by looking at the open end of the carburetor and seeing if the butterfly is closed or if it is opening as the engine warms up. A stuck choke will cause your lawn mower to not stay running every time.
The last thing is the ignition system. Your ignition coil could be heating up and malfunctioning. When an ignition coil breaks down, it will stop producing power to the spark plug and it will die at that point.
By checking these items one by one, you can narrow down what the problem is and get your lawn mower running once again.
This is an all too common with lawn mowers and I will give you some tips on how to resolve this.
A lawn mower that runs and then dies quickly is generally caused by a fuel issue. When a lawn mower first starts, the choke aids the carburetor in getting an extra amount of fuel to get the engine going. While the engine is running in this choke mode, fuel is being routed through the choke circuit primarily.
As the engine warms up or speeds up for engines that have a air vane lever that is moved by the spinning of the flywheel, the carburetor transitions from the choke mode to the main jet.
Here is an easy test. If the mower will run on partial choke and continue to run, then this means your main jet is plugged up and not letting fuel through it and therefore starving the engine.
What needs to be done is the carburetor must be disassembled and cleaned very well. First remove the carburetor bowl and the bottom. It should have a 10mm bolt or a 1/2″. It may also have a fuel shutoff solenoid on it that needs removed and then a 14mm bolt that goes through the bowl.
Then you can remove the float and needle assembly by pulling the small dowel pin that holds it to the carburetor. Set that aside on a clean paper towel. Now depending on what the bowl looks like inside, this will determine if you continue or you buy a new carburetor. If the inside of the bowl has corrosion or fuel that has adhered to the inside of it, this would be one that you want to replace. Also dry and powdery looking residue in the bowl is a sure sign that you should consider replacing the entire carburetor.
If things look fairly good inside, then remove the main jet and emulsion tube that are inside the fuel tower that runs up and down through the carburetor. You will need a standard screwdriver with a thin blade to allow you to get to it.
If you have a brass bolt that held the fuel bowl on, this is your main jet. Now clean these very well with carburetor cleaner or brake fluid and be sure that the tiny ports are cleaned out. You can use a welder’s tip torch cleaner to aid in cleaning them. Just don’t enlarge with the file like end of the tip cleaners. You will also want to clean the needle and seat. A Q-Tip works well to push down to the seat and twist. A soft bristle brush and carb cleaner works fine for the needle.
Spray some carb cleaner into the ports inside the carburetor body and then blow everything out with an air compressor if you have one set to low pressure. Make sure the carburetor bowl has been cleaned out as well and then reassemble everything.
One thing you should do is also take a fuel sample in a clean glass jar to ensure that the fuel is good in your lawn mower and not contaminated with water. It should look crystal clean with a slight yellow appearance and have a strong odor.
After you re-install the carburetor and test run the engine, it should run at a steady rpm with no surging. If it does surge, you can either try to clean it again or opt for replacement. You can also try to snug up the carburetor bolts to make sure it seals well. Be sure to replace the gaskets on both sides of the carburetor if you replace it.
By giving your carburetor a thorough cleaning, it should resolve my mower runs for a while and then dies issue.
First lets determine what the term “locked up” actually means. When an engine is locked up, it means that the crankshaft will not rotate and is stuck or locked up in that position.
Is the engine low on oil?
There are different things that can cause a lawn mower engine to get locked up and the first one is a lack of oil. When a lawn mower comes into our shop one of the first things we do is to check the oil and if there is none on the dipstick or it we barely see any, it usually is not a good sign.
Running any engine low on oil causes the bearing surfaces to not get any lubrication and they become very hot and wear quickly. If they become hot enough, they will actually weld the connecting rod to the crankshaft or the piston pin. In that case, the engine is most likely junk and it is cheaper to replace it or the lawn mower.
If there was a small amount of oil on the dipstick, the engine may have only partially seized up and is still usable. It will just need to be broken loose by removing the spark plug wire and gently turning the blade on a push or self-propelled mower. If it breaks loose without a great deal of effort, then you will want to add oil and run the mower and then change the oil again. Running the mower for a while to ensure that it is not making any knocking sounds or is down on power is important as you don’t want to throw a rod out of the block.
Are the push rods connected to the rocker arms and adjusted correctly?
An engine with loose push rods can cause the engine to lock up. One push rod will fall off of the rocker arm and then the cylinder will have high compression and no way to relieve it.
Is there raw gas in the cylinder?
A cylinder can also fill with gasoline that is leaking from the carburetor and cause the engine to hydo lock. You turn the key and try to start your riding lawn mower and it turns 180 degrees and then stops is a sign of a hydro locked mower engine. First you need to repair the carburetor that is causing this issue and then remove the raw gas out of the engine cylinder.
Is there something that is stopping the blade?
Other things that can make the engine lock up are a large amount of grass under the deck or a rock or stick caught in the blade. Check under the deck and be sure to pull the spark plug wire off before you do.
Is your pull starter or electric starter broken?
Your pull starter or electric starter can break while it is engaged and cause the engine to lock up. On a riding lawn mower you can remove the blower cover and see if the starter is stuck in the engaged position. You can do the same for a push or self-propelled lawn mower.
Is something inside the engine broken?
This is something that is an unknown because you cannot see if the camshaft or something else has broken and is binding inside the engine. This will require disassembly to determine what is damaged and needs to be repaired.
By carefully looking for these clues, you can determine why my lawn mower locked up.
This is one of the most frequent problems with a lawn mower and especially if it has sat over the winter. Depending on where it stayed over the winter could add to the problem. If it was in an unheated shed for example, the battery could have run down or mice may have chewed your ignition wiring.
In many cases it is the fuel itself that has gone bad. Over time fuel becomes stale and the lighter part of the fuel will evaporate which makes it very hard to ignite. The fuel will then begin to phase separate into different parts and dry up which plugs up the ports in the carburetor. This will cause your lawn mower to not start. The only correct way to resolve this issue is to clean the carburetor and properly dispose of the fuel in the gas tank.
Your ignition system could also be the problem for your lawn mower not starting. Your ignition coil could be bad or the spark plug as well. The kill system could also be malfunctioning causing a no spark condition. A key switch or safety switch could also be the culprit and by testing them out with an ohmmeter, they can be ruled out if they are in working order.
Those are the main things that cause a lawn mower to not start when it should. By inspecting and diagnosing them one at a time, you can rule out which items are good and which are not.
