Free Troubleshooting tips
that could help you repair your lawnmower or small engine today.
Man can and will $ave you
Thatís a Promise...
"Disconnect your spark plug wire and ground it before
doing any work."
Please read your ownerís manual through and through before using and
or doing any work on your equipment.
When lifting your lawnmower on its side always lift from the
carburetor or air filter side up so the oil and gas does not ruin
the filter. Reasons to lift lawnmower include changing oil,
sharpening or changing blade, or to clean under mower.
Safety while working or using a lawnmower
Be sure to wear eye protection at all times while working on or
using lawnmowers and small engines.
Always wear full shoes when cutting grass.
Never leave a running lawnmower unattended.
I do not recommend cutting wet grass. The lawnmower engine will have
to work twice as hard. The grass will also stop up your side
discharge. The lawnmower should always be cut off before cleaning.
Never reach under the blade housing if the lawnmower is running. Not
knowing how close the blade is to the side discharge, and you try to
unplug the hole you could dismember your fingers or hand.
5. Let your small
engines cool off for at least 10min before refueling.
Dispose of all harmful fluids at proper recycling plants.
Keep all people and animals away from running lawnmowers.
Helpful troubleshooting tips Start NOW:
First check the air filter. Is it getting air and gas? If not lets
find out why.
Air Filters; There
are 2 types. One is made of paper and the other is made of foam.
NOTE: (Whenever you lift your
lawnmower for any reason disconnect your spark plug and ground it.)
NOTE: Do not run your engine or any engine without the air
filter, it will RUIN the motor. When lifting your lawnmower on
its side, always lift it with the carburetor up. A little oil
Will come out, but not enough to hurt anything. If you lift your
lawnmower with the carburetor down oil & gas will go everywhere. If
your air filter is made of paper the oil & gas will ruin it. If not
you will have to clean your foam one.
Paper filters cannot be cleaned with gas or any solvent, you can
only use compressed air to blow the dirt out. If it's very
dirty, it's best to replace.
Foam filters can be cleaned with dish washing liquid and water
and dried with a rag. Then very liberally, work new engine
oil throughout the air filter and squeeze out excess. The
oil in the filter is what traps the dirt. If your foam filter is
deteriorating or coming apart replace it, it can ruin your
engine. Clean every 25 hours under normal conditions.
Use the same type of engine oil you use in your small engine to
lightly oil your filter.
Check your gas cap. The gas cap is a source of ventilation for
the fuel tank. If your gas cap is clogged it will make your fuel
tank vapor lock, and you will have no gas flow. To check and
see if the gas cap is bad, loosen the gas cap and see if it will run
longer than before you loosened the gas cap. If it continues
running, you need to replace the cap, if it does not continue
running check further in this troubleshooting guide for more
Is the fuel line clogged or partially clogged? Example: when
you disconnect the fuel line from the carburetor and the gas is
steadily flowing there is not a problem. But if it only drips with a
full tank of gas replace it after checking the gas cap.
Do you have a fuel cut off? If so, is it cut on?
5. Do you have a gas filter? If so is
it clear? If not, replace it.
6. Is the gas flowing in to the
carburetor? If not you could have a piece of trash in the
needle & seat. The needle & seat controls the gas flow that
starts & stops the gas. You will have to clean or replace. Itís best
The float controls the gas level in the carburetor. If any of
these signs occur, the carburetor is overflowing out of your air
filter or out of your primer. If you have gas in your oil, you
have carburetor problems.
NOTE: Drain the oil if
there is gas in it, if you donít it can be dangerous. You need
to check the needle & seat to see if it has trash or is bad.
Is your float bad? To check the float pull the pin that holds
your float in place, shake the float and if there is fluid inside of
the float, replace it. Donít forget to set the float level.
8. Carburetors with primers represent a large majority of
lawnmower and small engines today. They have primers to push
or force air in the carburetor and in turn force gas through the
center jet to make starting easier. Then look to see if the primer
is pumping gas in to the engine.
Things to check for if the primer is not working. This applies to
several different types of engines. Check for holes or tears if you
have a carburetor that has a diaphragm. (A diaphragm is a gas
pump located in carburetors that have the gas tank and carburetors
assembled together.) Replace the diaphragm if the diaphragm
has a hole or has hardened or slightly slid over to one side, or if
the engine will not run correctly and is skipping, not priming, or
will not run at all. If you have a float type carburetor, the
bowl gasket Will not be sealed properly and air will leak past the
bowl gasket and will not prime. If you have a air assembly
primer box where the air filter box is connected to carburetor, your
gasket Will not be sealing correctly. If there is a tear or a
hole in the gasket, air will leak past it and will not force air in
the carburetor which will not force gas through the center jet.
Also your air assembly box Will have a crack and will be warped
because it was over tightened. If so, replace it.
10. Some models have chokes.
Chokes are used to draw gas through the center jet to run. If
the choke is not working properly and it is not closing all the way
the engine cannot draw gas through the center jet and will not
11. The throttle cable is what operates
the choke on some models and the primer on some others, but it works
the speed of the engine. To adjust the throttle that works the choke
you need to loosen the throttle and open the throttle all the way,
then push it until the choke is closed all the way. To adjust
a "speed only" open the throttle all the way and make sure that the
engine speed will be all the way open and then tighten the cable
back up on the engine. Make sure if you have a kill switch on
the throttle cable, that it works when you lower the speed all the
way. If not, adjust again.
Carburetors: Carburetors are the cause of 99% of all small
engine problems. Carburetors are the easiest thing to repair on
We have videos
to that will help you in the repair of your Lawn Mower and Small
Section 2 Troubleshooting safety switch system
Spark. There are several things that would keep a lawnmower
or small engine from sparking like the safety switches.
Lawnmowers and small engines have several different locations where
the safety switches Will be. If your lawnmower or small engine
doesn't spark you need to get your owner's manual and find out where
your safety switches are and then try to trace the problem.
If you have one ... The oil sensor will make your lawnmower or small
engine quit running until you fill it with oil to the "full level."
This will cause the engine not to spark because of the oil being
NOTE: This is a safety
feature to protect your engine from running out of oil.
Stop cable or blade brake. This cable is connected to the
handle bar and you have to hold the handle bar down for your engine
to run. This cable becomes stretched after some time and needs
to be replaced. There is a safety switch on the other end of
that cable, on the motor, that Will not be opening all the way and
in turn, not letting the engine spark.
Coils. Lawnmowers and small engines have changed a lot in the
last 15 years. 99% of all lawnmowers and small engines today have
electronic ignition coils which means no points. When you
start your lawnmower or small engine and it runs until it gets hot
and won't start back again until it cools off you Will have a bad
The oil is the
most important fluid in your lawnmower and small engine. Oil in
small engines needs to be changed at least every 25hrs. The
viscosity of oil wears out from the high heat the small engines put
out. If you change your oil more often your small engine will
last much, much longer. See your owners manual for the proper
type of oil the engine needs and different climates use different
grades of oil.
Florida Will be 90 degrees mowers will use a thicker oil. In upstate
New York where there is 35 degrees temperature, mowers & small
engines will use a thinner oil for easier starting and
lawnmowers and small engines use the same type of oil. They have
ratings to follow like API, SL, SJ, SH, SG, SD, MS etc....
automotive oil's will meet the type of oil that your small engine
needs. Please consult your owner's manual to be sure the type is
correct. Itís best to change your oil when your small engine is
Blades. All blades basically are the same and most all blades
will sharpen about the same. I have found that a 30 degree
angle is best for lawnmower blades. NOTE:
All blades must be level or balanced before putting them back on
your mower, if they aren't your lawnmower will vibrate. If
your blade is bent, replace it. Do not try to straighten it.
The blade must be the right blade for the lawnmower. DONíT, try to
make a blade work if it is not right. If you have a blade on
your mower that is not made for your lawnmower it could come off and
seriously hurt, dismember, or kill someone. Do not take or add
any washers unless whatever you are adding is made for the mower
blade. The proper bolts for a blade are grade 8. Donít
try to use any other type of bolt. All blades must be torqued down
to the specks that are in your owner's manual.
The methods and
techniques explained will apply to push mowers, riding mowers,
tillers, go-karts, minibikes, generators, pressure washers, log
splitters, shredders, edgers, walk behind blowers, and essentially
all small single cylinder residential and commercial (one spark
plug) engines 3hp-18hp etcÖ.
Thank you for visiting my free troubleshooting site.
Learn all these procedures and much more with the Lawnmower
winning videos. Don't spend your hard earned money at the lawnmower
shop learn to do-it-yourself