John Deere
The engine stalls out back fires out the exhaust then it can be restarted
Experienced gardeners share their insights in answering this question :
Charlene: According to https://www.briggsandstratton.com/us/en/support/faqs/engine-backfire-afterfire ”
What causes a small engine backfire & how do I fix it?
Backfire typically occurs when the engine is decelerated rapidly.
Common Causes of Backfire:
Lowering engine speed too fast
Gasoline, which contains higher blends of alcohol
Carburetor adjustment set too lean
Muffler construction can induce backfire
Higher than normal engine temperatures
Some carburetors can induce backfire due to the sensitivity of internal transitional passages
(This condition cannot be corrected).
Possible Fixes for Backfiring:
Lower engine speed slowly
Follow small engine fuel recommendations and/or switch to brands with low or no alcohol
Adjust carburetor for optimum performance
Inquire with equipment manufacturer about increasing air volume to decrease engine temperature”
Charlene: I hope that helps! 🙂
Charlen
How to Identify and Fix Common Gardening Problems ?
We provide a variety of viewpoints on how to identify and fix common gardening problems. Our sources include academic articles, blog posts, and personal essays from experienced gardeners :
A spark plug that is damaged, worn, or has an improperly set gap between its electrodes creates a weak spark. As a result, the fuel may not ignite in the cylinder, but it might ignite when it reaches the hot exhaust muffler. The result is a loud backfire. Poor spark also results in a mower that runs unreliably.
Backfire, or more accurately “after fire” when it occurs when stopping an engine, is caused by unburned fuel/air mixture being ignited by the heat of the muffler.
Carburetor adjustment may not be properly set for correct engine performance. Anti-afterfire solenoid may not be working properly.
If you were to be dumping too much fuel through a carburetor into your engine,” says Louwerens, “then what happens is you`ve got too much fuel, it didn`t burn it all, then it ends up igniting at the wrong time, and then you get that backfire effect.”
Working Too Hard. Your lawnmower may backfire simply because you are working it too hard, either by cutting grass that is too long or running it with dull blades. This can slow the movement of the piston, which falls slightly out of phase with the firing cycle of the spark plug.
Another possible cause of your backfire is a spark plug refusing to “spark” when the exhaust valve opens. If the air/fuel mixture has become too rich, unburned fuel is left in the exhaust system. The misfired spark plug ignites the rich air/fuel mixture, causing a loud “bang” in the tail pipe.
The spark inside the chamber may not burn up all the fuel, allowing a little extra gasoline vapor to enter the exhaust, and lead to a backfire. This can be caused by a faulty mass airflow sensor or a clogged engine air filter “choking” the engine and not allowing enough oxygen to flow into it.
On the other end of the spectrum, a bad fuel pump, vacuum leak, or clogged fuel injectors could cause an air-fuel ratio that`s too lean; that is, it has too much air and not enough fuel. Though this is the opposite problem, it can also cause a backfire as vapor escapes into the exhaust and combusts there.
Backfiring or overheating
Engine backfiring and overheating are other common symptoms of a potential problem with the carburetor. If the carburetor has any sort of issue that results in it delivering a lean mixture, a mixture that does not have enough fuel, it may result in engine backfiring or overheating.
Clogged or Dirty Air Filters Dirty air filters are one of the most common reasons lawn mowers sputter. Dirt can be present in the apertures that lead from the carburetor and the fuel filter and interrupt the flow of fuel supply to the combustion chamber. You want to be sure to clean or replace dirty air filters.
Clogged or Dirty Air Filters Dirty air filters are one of the most common reasons lawn mowers sputter. Dirt can be present in the apertures that lead from the carburetor and the fuel filter and interrupt the flow of fuel supply to the combustion chamber. You want to be sure to clean or replace dirty air filters.
Another possible cause of your backfire is a spark plug refusing to “spark” when the exhaust valve opens. If the air/fuel mixture has become too rich, unburned fuel is left in the exhaust system. The misfired spark plug ignites the rich air/fuel mixture, causing a loud “bang” in the tail pipe.
The spark inside the chamber may not burn up all the fuel, allowing a little extra gasoline vapor to enter the exhaust, and lead to a backfire. This can be caused by a faulty mass airflow sensor or a clogged engine air filter “choking” the engine and not allowing enough oxygen to flow into it.
One of the most common causes of a sputtering engine is an issue with the vehicle`s fuel system—the filter, pump, and injectors. These three critical components work together to ensure fuel flows smoothly from the fuel tank to your engine`s fuel injectors, and then pumps into the engine evenly.
Discover Relevant Questions and Answers for Your Specific Issue
the most relevant questions and answers related to your specific issue
Lawn mower cranck but wont start…
ANSWER : Since you already checked for spark and air I would drain all the fuel out of it and check that fuel for water. Over time some lawn mowers end up with contaminated fuel. You can see the water sitting on the bottom of the fuel if you let it stand for a bit in a small plastic bowl.
Be sure to empty and dry out you fuel can as well. Especially if the mower stopped running right after a refuel. Which is a good sign your gas can is contaminated too.
How do i add transmission oil – Ariens Lawn Tractor 46"" Riding Lawn Mower 936053"
ANSWER : Should a plug or cap on top of transaxle.
Bosch electric lawn mower wont start, how do I fix it?
ANSWER : Cable damaged …renew cable . ..if does not work try condenser.
I have trouble starting a toro walk behind mower
ANSWER : All, I thought my carb was shot, so I replaced it. Still, start but no run (and had to use starting fluid). THEN!!! I noticed the spring to the “rev limiter” (just below and towards rear of carb) was not “tight”. The stupid bracket that holds the end of that spring had been bent down ~1/16″ and that caused all this heartache. CHECK YOUR REV LIMITER!!!
Lawn mower motor runs good, the drive wheels run good but the blade won’t stay enguaged. Thanks
ANSWER : Check your cable that controls the blade engagement.
Lawn mower will start and run for 5 seconds and shut down
ANSWER : Will it stay running with your choke on? if so then clean your carb. if not then look for a blockage from tank to carb. ie fuel shut off, deteriorated fuel line. plugged filter etc
Lawn Mower Won’t Run
ANSWER : Ya didn’t give much info but it sounds like the carb had plenty of time to varnish up. take the carb off and clean it make sure you take the fuel bowl off and clean the floate and floate needle good. an auto parts store will have what you need to do everything with
Will not start turns over has spark the engine was running and killed and will not restart
ANSWER : If you have good fuel to the plug and a good spark and it still does not start it could be a timing issue, check the flywheel key has not sheared.
