My lawnmower won't start again.
It is a four stroke Honda, the fuel supply is OK, the spark looks OK
when I take the plug out and rest it against the cylinder head and
pull the cord.
However, I know from experience, that as soon as I go down and buy a
new spark plug, the mower will work again. The plug seems to need
renewal, even though I have a small lawn, and it would have done no
more than 10 hours work, maximum.
What life do others get out of their plugs? Could I be missing
I have a LARGE lawn and live in the Pacific Northwest where the ample rain
makes the grass grow like mad. I think I last replaced my lawnmower spark
plug 3 years ago. I check it each Spring and clean it up a little. The
mower starts first time, every time.
This is Turtle.
I have been down that road a bunch and the only thing that was told to me by
a small engine repair fellow on this was : A small engine will flood out or
get the spark plugs soaked in gas and or oil for a while and it does
something to the white part , I guess ceramic stuff and it will not hold
back the electricity and just not make it fire at the points. The gas will
kill the insulating propertys and make it not fire right. So just change the
plug every year and live long and prosper.
<< This is Turtle. >>
<< it does something to the white part , I guess ceramic stuff and it will
not hold back the electricity and just not make it fire at the points. >>
Turtle is absolutely correct, as all pro mechanics know. If the condition is
endemic in any engine, the solution is to match the spark plug heat range to
the engine operating conditions. First option, try a hotter plug (use the
manufacturers charts). Next option, use better air filters. Cheap ones tend to
make engines run too rich and foul the plugs. HTH
In a 4 cycle lawn mower--10 years at about 1 hour per week
for a minimum of 25 weeks. In a 2 cycle chain saw-- 8 years
of actual run time of about 16 hours per year. Nothing
should wear out in 8 hours of use, but something could
break. Most likely it's corrosion of points, switch, etc.
and repeated start tries wears the corrosion until good
electrical contact is made. BUT, it could be failure of an
I have a Rumely Oil Pull tractor that was made in 1927 . It is ran ever yera
in 90+ degree temps. It is finally on it 2nd pair of plugs as of 2 years
So, either they don't make them like they used to (probably the case) or you
have something else wrong.
If the lawnmower is sitting all winter without being used, the spark plug
may gum up. You can try to clean its contacts with some crocus cloth of a
medium find grade. I would prefer to change the plug every season, for
If the spark plug is getting gummed up during the times of use, then you
have a problem with the motor. It is possible that it is not burning the
fuel properly, due to bad rings or seals, or you are using low grad fuel in
it. This means a motor rebuild.
Peter ( email@example.com) writes:
What colour is the tip area of the plug? If it's sooty then the mixture
could be too rich. Is the exhaust smoky when it's running? Starting could
be difficult if you are trying first thing in the morning when the mower
is covered in dew. Do you have better luck if the mower sits in the sun
until it's good and hot throughout?
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