According to the searspartsdirect web site, it costs about $15 for a new
lawn mower blade for my Craftsman 917.388853 6.5HP 21" push lawn mower
(Briggs & Stratton engine 123K02-0444-E1), plus 10% sales tax & 10 dollars
shipping. I'm sure it will cost double or triple that to have someone else
sharpen it, assuming standard labor rates of $100 to $200 an hour out here.
The owners manual (on page 12) recommends against sharpening the blade.
http://www.managemylife.com/mmh/lis_pdf/OWNM/L0505023.pdf
The blade seems to cut well no matter how many rocks I hit (I have other
problems like a sheared flywheel key, but the grass was getting cut even
with a five-year-old dinged up blade).
My question is:
Does anyone bother sharpening a blade?
The reason I ask is it will likely cost more to have someone sharpen the
blade than the blade costs and my blade seems to cut as well now as when
new five years ago, even after countless rocks and tree stumps have been
"mulched" by the blade. Those things are practically indestructible.
Do you bother to sharpen your blade? Why?
========================================================
Couple of years ago used to cost $3 to $4 around here. Biggest job is
often getting the blade off!
Easy enough to do on a bench grinder or in a vise with a big
'bastard'' file.
But make sure the blade is balanced afterwards.
Recently modifying and rebuilding a mower was able to shorten a blade
by grinding off the ends and then sharpen it.
> Dull blade does a poor job of cutting. It just beat up the grass blades.
I think I'll learn how to sharpen my blade and see if it makes a
difference.
Interestingly, this video says the blade is the flywheel ... and that the
"flywheel" at the top is really just a cooling fan.
http://www.youtube.com/watch?v=P-QINnsFYw0
Interesting.
This video is from a very experienced lawnmower mechanic who advises
against removing the blade to sharpen it.
http://www.youtube.com/watch?v=HDQ0elcCOlY&feature=channel
The owners manual recommends removing the blade if it's gonna be sharpened.
Why?
Why do all the manuals recommend removing the blade to sharpen it while
this admittedly very experienced mechanic says not to bother?
>On Mon, 5 Jul 2010 23:53:26 -0700 (PDT), terry wrote:
>> Couple of years ago used to cost $3 to $4 around here.
>> Biggest job is often getting the blade off!
>
>This video is from a very experienced lawnmower mechanic who advises
>against removing the blade to sharpen it.
>http://www.youtube.com/watch?v=HDQ0elcCOlY&feature=channel
I can't watch the video now but I presume he counts the number of
strokes he uses and has enogh practice to make sure the strokes are
with the same amount of pressure and the same distance from the center
on each end. That is 2 strokkes at 8 inhces, 2 strokes at 7.5 inches,
2 a5 7, etc. on both ends of the blade. If one did that well enough,
evenly enough, the blade would still be balanced when one was done.
>The owners manual recommends removing the blade if it's gonna be sharpened.
>Why?
AFAIK, so it can be balanced afterwards.
Strange. The thing at the top does have a fan, but which has the
greater angular momemum? Or the bigger integral of distance from
center x mass for the whole diameter of the blade versus "flywheel".
I don't know. The length of the blade is greater than the diameter at
the top, but the thing at the top is a whole circle and pretty thick,
not just a thin blade 2 inches wide or so.
Whichever's is greater could be considered the flywheel, I guess,
because it does more to keep the engine spinning smoothly, even though
it's a one-cylinder engine.
> I can't watch the video now but I presume he counts the number of
> strokes he uses and has enogh practice to make sure the strokes are
> with the same amount of pressure and the same distance from the center
> on each end.
He doesn't use a file. He uses a hand-operated grinding wheel (DeWalt
type). It is interesting to note how he does it w/o removing the blade.
Dull blades rip the grass and will burn the top in hot summer, it
takes about 15 minutes to use a file yourself.
Yes (3 blades, riding mower), sometimes.
> Why?
Cuts better. Briefly.
I don't do it as a matter of course, just if I happen to have to drop the
mowing deck for something else. And if you think blades are indestructible,
you should see mine after a season or two...not much left.
--
dadiOH
____________________________
dadiOH's dandies v3.06...
...a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico
Shears aparently lives on the residual income of off-spec parts. Their
mowers won't accept Briggs or Tecumseh parts in many cases, so you end
up going to Shears and buy their parts.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"James H." <hall....@sbcglobal.net> wrote in message
news:i0uhi9$deu$1...@speranza.aioe.org...
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"James H." <hall....@sbcglobal.net> wrote in message
news:i0uk3m$gs4$1...@speranza.aioe.org...
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"James H." <hall....@sbcglobal.net> wrote in message
news:i0ukp5$hka$1...@speranza.aioe.org...
I sharpen mine occasionally with a hand grinder. I never bother with
the balancing.
I sharpen mine every spring. Nothing cuts like a sharp blade. (that's
why) Dull blades just tear the grass. If you keep them sharp it doesn't
take long on the grinder. If you wait until it's blunt, it may take a
while to get the cutting angle planed and edge sharp again. Like any
other maintenance, let it slide and it's more work to get back into
shape. It also pays to clean up your lawn and remove the rocks. If you
never hit stuff it stays fairly sharp. I like a knife edge.
--
LSMFT
I haven't spoken to my wife in 18 months.
I don't like to interrupt her.
> The mechanic never mentioned that you
> should always remove the sparkplug when messing with the blade.
> Compression can bump a blade enough to do damage.
Hi Jim,
Thanks for watching the video. I should have mentioned it was about 4
minutes in that he sharpened the blade. I appreciate your time and effort.
I wouldn't remove the sparkplug; but I would pull the wire off the spark
plug (and yes, the mechanic didn't mention that).
He ground the upper part of the blade and then the lower part briefly with
the angle grinder but I agree he didn't balance it afterward.
The owners manual I have says to hammer a nail protruding out of a wall
stud and hang the blade horizontally on that nail from the center hole to
balance.
So, even if I sharpened the blade on the mower, I'd still have to remove it
to check the balance. I guess he has so much experience that all his checks
showed his blades were still balanced after he sharpened them.
> I sharpen mine occasionally with a hand grinder.
> I never bother with the balancing.
I've never sharpened a blade before.
May I ask:
If I sharpened the blade, and if it was slightly unbalanced, would I know
it was unbalanced when I started up the lawn mower?
If yes, then there's less reason to balance ahead of time; if not, then why
bother balancing?
Yes, of course. I'd like to do it every year, but I tend to only get around
to it every other year. Same as with the oil (I do top it off a few times
every year, though, if it's low).
Jon
> "flywheel" at the top is really just a cooling fan.http://www.youtube.com/watch?v=P-QINnsFYw0
>
> Interesting.
And the magnito or ignition.
Interesting. The left side says to keep the blade sharp, the right side
says they don't recommend sharpening. Maybe they mean DIY versus a pro
doing the sharpening.
Sharp blades do cut better while the dull ones chop and tear the grass
apart. I happen to have a belt sander and it does a good job quickly.. A
grinding wheel is a bit harder to handle, a file works too. It does not
have to be perfect like a butcher knife, but it all helps. Take the same
number of passes on both sides to help keep it balanced.
I, personally, do not sharpen my blades. Never have. But if I were to do
it, I have about six tools that would do it without me having to remove the
blade.
Steve
visit my blog at http://cabgbypasssurgery.com watch for the book
I can't imagine paying someone to sharpen a blade. I sharpen our push
mower and the double blades on our garden tractor /mower and it
doesn't take that long. I do the serious sharpening with my bench
grinder, then dress them with a hand file. It probably takes more
time to dismount and remount the blades than to sharpen them.
By the way, if you are hitting rocks, stumps or such you might want to
clean up the yard a bit. One good "thunk" will bend the crankshaft,
and/or take out the lower bearing on most push mowers. Then you don't
have to worry about the blade :^)
RonB
I've watched people balance them but I just don't see any reason to.
I think they would have to be grossly out of balance to matter. I
don't try to grind out any really huge nicks. If 90% of the blade has
a sharp edge I quit. After about a 1/4 of the blade is gone I buy
another one. My old lawnboy got retired to our lake house about 8
years ago where it's now 18 years old. Never balanced a blade on it
in that whole time. I'va had to put a few parts on it but never any
motor internals. May matter more if you are a pro running your
equipment 6 - 8 hours a day.
I sharpen my own blade about once a season. A sharp mulching blade on my
Snapper cuts much cleaner, accurately and mulches much more effectively than
a dull one. It take me about 5 minutes remove blade, 5 to put in vice and
sharpen with a file and another 5 to replace. Have done this for at least
the last 25 years.
It might be a dollar extra for the fools who mulch countless rocks and
stumps:)
> Here in CT usa a plain rotary mower blade is resharpened and balanced
> for $6.25 and a mulching blade for 7.5
This morning I called the Briggs and Stratton recommended lawnmower shop
for my zip code (95134).
They told me it will always costs me $45/half hour shop rate for anything
they do.
Therefore, they recommended I try to have other work done because a half
hour is their minimum charge.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"jamesgangnc" <james...@gmail.com> wrote in message
news:212cb235-44f3-418d...@k39g2000yqb.googlegroups.com...
I can see where it can take a half hour to remove a blade that has not been
off for years. If it is a quickie, get the oil changed at the same time to
get your $45 worth.
Yes that is true, I learned that in shop class back around 1970.
Engines with no direct mounted blade normally have a cast iron flywheel,
or some kind of flywheel with some weight to it. However, if the motor
is worn and doesn't have a lot of compresion, it will run with the blade
removed. And it'll scream like a 2 stroke! Did that as a kid with a
little 3 wheeled riding mower that was about shot. Wasn't worried if
the engine blew.
Of course. If it didn't work better when sharp, they would sell new
ones dull.
They are probably listening to one of their lawyers that see danger in
the home owner sharpening their own blades.
>The flywheel contains a magnet that passes by a coil and induces a
>voltage in the primary of the coil.
While you have the flywheel off, clean any surface rust from the
magnets and on the ignition. A fine sandpaper will work.
Once had a magnet fall out of the flywheel. Forget what I used to
secure it with. (Glue?)
--
cut the grass too the roots and go fishing
> It take me about 5 minutes remove blade, 5 to put in vice and
>sharpen with a file and another 5 to replace. Have done this for at least
>the last 25 years.
Roger that!
5 minutes with a file I can even get the nicks out.
My walk-behind mower cuts more quietly with a sharp blade because the
governor calls for less throttle. It means fewer gas stops and a cooler
engine. A sharp blade produces less of the sticky pulp that tends to
build up and clog a mower.
If you pay somebody to sharpen it, you also have to take the blade to him.
Once I have a suitable wrench in my hand, removing the blade of a
walk-behind mower is very quick. I sharpen with a side grinder. I take
care not to overheat the edge, but I'm not sure if overheating will
leave the edge softer. I finish up with a big ceramic hone. After
installing a blade, I measure the height of a blade tip, rotate 180
degrees, and make sure the other tip is at the same height. Uneven
heights would mean vibration.
He doesn't advise against removing the blade. He says 'HE" doesn't
remove it.
> The owners manual recommends removing the blade if it's gonna be sharpened.
> Why?
>
> Why do all the manuals recommend removing the blade to sharpen it while
> this admittedly very experienced mechanic says not to bother?
>
Again, he is showing an alternative to sharpening without removing the
blade. He doesn't say NOT to remove it. Do you have one of those grinders?
--
Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeroes after @
> He doesn't advise against removing the blade. He says 'HE" doesn't
> remove it.
Good point.
> Again, he is showing an alternative to sharpening without removing the
> blade. He doesn't say NOT to remove it. Do you have one of those grinders?
Yes. I have a Dewalt grinder just like that, only my stone is new (his was
old and maybe old is better).
I also have dremel tools and files but for now, I think we have our answer
on the sharpening:
a) Some people never sharpen; others do about yearly.
b) It won't make much different; but it might make some difference.
c) Almost everyone removes the blade to sharpen & balance; some don't.
d) Easiest balancing method I've seen is that which the Craftsman manuals
says to do which is to hang the blad on a nail horizontally.
e) A new blade (for my mower) is $14.50 + 10% tax + shipping to CA; while
the nearest Briggs & Stratton shop won't charge less than $45 to sharpen (I
didn't ask about tax) and I have to bring the lawnmower and/or blade to
them.
I remove the one nut holding the blade, which takes about 5 minutes, and
sharpen it with a bench grinder. I have more control on how much to
remove and I am able to balance it.
My 18 x 46 tractor's mower deck has three blades. I remove the whole
deck before winter because I have a snow blower attachment that goes on
the tractor.
I have all winter to remove and sharpen the three blades.
You might be able to get a replacement blade at HD or Lowes. Check
their one-line mower supplies.
I try to do it yearly, but if I forget I don't lose any sleep over it...
> b) It won't make much different; but it might make some difference.
I just replaced the blades on the lawn tractor - huge difference in cut
quality between new and old; I think the old ones often beat the grass
more than cut it, and it'd lay flat for a day or two and then spring back
up and look nasty.
> c) Almost everyone removes the blade to sharpen & balance; some don't.
Yeah, I've never done that on the lawn tractor - takes me about ten mins
to pull the whole deck, and I can get in there with a grinder to sharpen
the blades in-place (I've been known to sit the whole tractor up on its
butt instead, but my back hates me for it). I realise we're talking about
smaller mowers here though, but if there's space to get a grinder in I
can't see a reason to take the blade off.
> e) A new blade (for my mower)
> is $14.50 + 10% tax + shipping to CA; while the nearest Briggs &
> Stratton shop won't charge less than $45 to sharpen (I didn't ask about
> tax) and I have to bring the lawnmower and/or blade to them.
I paid $6 per blade at a local farm supply place; cheapest I'd seen
online were $15 (without shipping cost) for the same thing. Having said
that I really should have bought mulching blades, and I think those were
$9 each.
cheers
Jules
> On Tue, 06 Jul 2010 00:40:31 -0600, Tony Hwang wrote:
>
>> Dull blade does a poor job of cutting. It just beat up the grass
>> blades.
>
> I think I'll learn how to sharpen my blade and see if it makes a
> difference.
Only your grass will know the difference. It will be cut off cleanly rather
than torn.
I wedge the blade still on the mower, and then use an ordinary socket and
ratchet to remove the bolt. I use a 6" bench grinder to put a new edge on
the blade.
You'll find that all mower blades come balanced from the factory. That's
why you'll see odd corners cut off on the ends of the blades.
To re-balance a blade: Hammer a 3" nail into a stud so that it's parallel
with the ground. Hang the blade on the nail from its bolt hole, making sure
it's centered on the nail. Take note of which side is heavier, and grind a
corner down a bit on that side. Recheck and refine as necessary.
--
Tegger
<replying to my own post, here...>
>
> You'll find that all mower blades come balanced from the factory.
> That's why you'll see odd corners cut off on the ends of the blades.
But not always. My current mower's blade was balanced by cutting off the
entire end of the blade, so one side is shorter than the other by about
1/16".
>
> To re-balance a blade: Hammer a 3" nail into a stud so that it's
> parallel with the ground. Hang the blade on the nail from its bolt
> hole, making sure it's centered on the nail. Take note of which side
> is heavier, and grind a corner down a bit on that side. Recheck and
> refine as necessary.
>
>
>
Grind a TRAILING corner, by the way.
I use a disc-shaped stone meant for axes in order to lightly dress the
freshly-ground edges. You're not sharpening a butcher knife here, so the
edge you end up with just needs to be sharp enough to cause some pain when
you press your thumb into it, but it doesn't need to be so sharp that it
breaks the skin.
I just went and had a look at the nail I use for balancing, and it's a
1-1/4" finishing nail, not a 3".
And finally, UNPLUG electrical cord or spark plug before turning the mower
over!
--
Tegger
Because it costs nothing, and takes way less time than running out to 5 shops
trying to find the right blade. Sharpening a blade probably takes 10 minutes.
> I really should have bought mulching blades, and I think those were
> $9 each.
The prices you quote seem like Kansas prices ... not California prices
(which are triple anything quoted so far) ...
But, may I ask ... What is the difference between a MULCHING blade and a
regular blade?
Are they interchangeable?
Mulching blades usually have a higher lift / blade tilt to them
>
> On Mon, 5 Jul 2010 23:53:26 -0700 (PDT), terry wrote:
> > Couple of years ago used to cost $3 to $4 around here.
> > Biggest job is often getting the blade off!
>
> This video is from a very experienced lawnmower mechanic who advises
> against removing the blade to sharpen it.
> http://www.youtube.com/watch?v=HDQ0elcCOlY&feature=channel
>
> The owners manual recommends removing the blade if it's gonna be sharpened.
> Why?
>
> Why do all the manuals recommend removing the blade to sharpen it while
> this admittedly very experienced mechanic says not to bother?
Start quote: It's too much work. End quote
--
Tekkie Don't bother to thank me, I do this as a public service.
And the generic mulching blades from the big-boxes here don't have
nearly the 'wing' on the back as the factory mulching blade. Don't seem
to work as well. I finally had the factory blade sharpened and put it
back on, but in less than one season, the grass looks like it is getting
dull again. Guess the old coot in the shack (saw sharpeners always seem
to be characters) ground past the hard part of the steel. One of these
days I need to hunt down a factory blade on line or at a real
small-engine shop.
--
aem sends...
I replace my blade( pushmower ) once a year. No sharpening
Jimmie
>But, may I ask ... What is the difference between a MULCHING blade and a
>regular blade?
A mulching blade won't require you to bag the clippings and send then
to the landfill.
Also, saves on the cost of bags.
>> I really should have bought mulching blades, and I think those were $9 each.
> The prices you quote seem like Kansas prices ...
> not California prices (which are triple anything quoted so far) ...
> But, may I ask ... What is the difference between a MULCHING blade and a regular blade?
A mulching blade produces grass that doesnt need to be collected,
it can be left on the cut grass to mulch into the cut grass.
http://en.wikipedia.org/wiki/Lawn_mower
> Are they interchangeable?
Yes.
> Is the blade different?
Yes.
> I had thought it was just that the body prevented the grass from discharching so it went round and round being re-cut?
If it was that, there wouldnt be mulching BLADES.
> Oren <Or...@127.0.0.1> wrote
It also makes mowing a lot faster since you don't have to stop and
empty the bagger. Beside, my ZTR does not have a bagging attachment.
--
Jim Rusling
More or Less Retired
Mustang, OK
http://www.rusling.org
> On Wed, 7 Jul 2010 14:15:46 +0000 (UTC), Jules Richardson wrote:
>
>> I really should have bought mulching blades, and I think those were $9
>> each.
>
> The prices you quote seem like Kansas prices ... not California prices
> (which are triple anything quoted so far) ...
I'm up in northern MN - cheap living up here!
> But, may I ask ... What is the difference between a MULCHING blade and a
> regular blade?
As others said, the blade shape's different, and designed to chop the
clippings up into little pieces. At the moment I end up with little rows
of clippings due to the regular blades I put on (no bagger on the mower,
and with a couple of acres of lawn it'd be a lot of clippings to deal
with anyway)
> Are they interchangeable?
The ones for my MTD mower are; there's a lot of clearance under the
mowing deck, and the mounting holes are exactly the same. I really don't
know why I just grabbed the regular ones off the shelf :-)
cheers
Jules
==
The mulching blades are "high lift" and often cost a bit more. They
are also made of high tensile steel. Buy the mulching blades even if
you never mulch.
==
I pile them up into a large compost pile. It may be 5 feet tall at the
end of summer, but by spring, it is down to about 3 feet tall. The
bottom of the pile has the blackest, richest soil that can be easily
shoveled out like it was the soil that Billy Mays used to tout the
Awesome Auger. :-)
> Also, saves on the cost of bags.
>
To follow up on this thread, I learned a lot, summarized as:
- It cuts better when/if you sharpen the blade
- Sharpen the blade off the lawnmower; balance it before putting it back
In the end, I bought a new blade from Sears ($15) but only because I was
also ordering a new plastic intake manifold and screws which were snapped
in half by my idiotic attempt at prying up the flywheel while banging down
on the crankshaft. NEVER DO THAT!
Nothing is gonna happen except aluminum and plastic stuff under the engine
will break. The part that broke is #50 (intake manifold, Sears PN 497465)
and #54 (intake manifold screw) on page 36 of this 40-page pdf (half of
which is in Spanish).
http://www.managemylife.com/mmh/lis_pdf/OWNM/L0505023.pdf
http://www.hammerwall.com/Download_Manual/14875/
http://tinyurl.com/32mzm2n
If you ever have to remove a flywheel like the one in my Craftsman 21" push
mower 917.388853 with a Briggs and Stratton 6.5HP 123K02-0444-E1 engine,
simply tap the two holes in the flywheel with a 1/4 x 20 tap, and use a
harmonic balancer puller and voila, the flywheel will come off.
Resist the tempatation to pry (you'll only break stuff) and bang on the
crankshaft (what's that gonna do anyway; the crankshaft isn't going to move
down?????).
When I pick up a screw extractor set, I'll remove the broken bolt; and when
the new intake manifold arrives, it will come with a new blade which will
solve my dilemma once and for all!
Thanks for all your advice; you guys are wonderful!
> Does anyone bother sharpening their lawnmower blade?
http://www.gadgetcorner.com/hardw/blade/blade.htm
"A dull blade will tear at the grass, damaging the blade tips and leaving a
whitish sheen across the lawn. But a sharp blade will make a clean cut
leaving a deep even green color over the entire lawn."
What is your climate? You don't have earthworms?
> The mulching blades are "high lift" and often cost a bit more. They
> are also made of high tensile steel. Buy the mulching blades even if
> you never mulch.
> ==
The blades on my mulching Toro have almost no lift compared to my bagging
Snapper.
There are many kinds of "mulching blades. Some have 2 blades, one 1/2" higher
than the other. Some have a downward forcing "fan" blade in the center to kick
the grass around more under the mower, and maybe force it down into the grass.
My toro is just a flat blade with the back corner bent up a tiny bit. One Toro
I've used had plastic lumps under the deck like "waves" to force the cut grass
back down.