Craftsman push lawnmower wobble after hitting rocks won't start
James H.
stationary object?
I've hit much tougher sets of rocks than the little things that all of a
sudden caused my Craftsman 18 inch push mower to wobble (I think) and run
badly and now it won't start.
No big deal. Lawn mowers are only a few hundred dollars, and a repair
person probably will only charge half the cost of a new one.
But, I wonder if I take it apart, what would I be looking for?
I've never taken a lawn mower apart but I've fixed things and have all the
mechanics tools for my car, for example, and a lawn mower can't possibly be
too complicated.
What would I be looking for. What is the typical thing that breaks when a
lawnmower hits an immovable object?
harry
IT sounds like the engine is unbalanced, therefor some rotating part
has broken off or the crankshaft is bent. Or possibly the engine has
come loose on it's mountings.
The obvious one would be the cutter blade. Check that it's running
without a wobble ie not bent.
Or, as it won't start something associated with the igntion system.
James H.
> IT sounds like the engine is unbalanced
Yes. Something went unbalanced but I checked (visually only) the blade
itself which seems to be all nicked up but no worse than it has been for a
loooong time.
> therefor some rotating part has broken off or the crankshaft is bent.
It could be a bent crankshaft. I guess. But, I've hit far worse than what
made this happen this time as it happened all of a sudden on me.
How would I know if the crankshaft is bent?
> Or possibly the engine has come loose on it's mountings.
I didn't think of that. Will check tomorrow but I didn't notice anything
loose as I flipped the lawn mower over to look at the blade.
> The obvious one would be the cutter blade. Check that it's running
> without a wobble ie not bent.
It doesn't look bent. It doesn't look like it's wobbling. Would that
prevent it from restarting? It ran for a few minutes "after the accident"
but roughly - and now it just won't start.
> Or, as it won't start something associated with the igntion system.
Could be. I don't see how that would be associated with hitting something
but as I said, it wasn't all that much that I hit (I've run over far worse
with that mower) so maybe something just broke in the ignition. I can pull
the plug and check.
FatterDumber& Happier Moe
Does it run?
If not the aluminum key was probably sheared, they are supposed to do
that so the flywheel isn't damaged and it helps prevent bent crankshafts.
If it runs the blade was bent or a small piece of the blade broke
off, the blade came loose(unlikely) the crankshaft was bent (I haven't
seen that happen in a long time).
We really need more details to help trouble shoot it. If it's running
and the blade isn't bent it's possible the blade just needs sharpening
and balancing.
ransley
If you are lucky its a bent blade and sheared flywheel key, its a Diy
job with a flywheel puller, if unlucky its a bent crankshaft and its
junk, do you cut at 3.5" or more, maybe its time to remove those
rocks. Not starting is the flywheel key hopefully it did its job,
sheared and saved the motor.
LSMFT
It's not a rock crusher.
--
LSMFT
I haven't spoken to my wife in 18 months.
I don't like to interrupt her.
Brent
> It's not a rock crusher.
Everyone hits rocks now and then with their lawnmower, probably once a day
or twice a day or more if you have rocky soil like I do. A good mower is
designed to handle rocks and pulverize them if they're small enough, and to
not be damaged if they're larger.
Notes on the Troubleshooting and Repair of Small Gasoline Engines and
Rotary Lawn Mowers, Version 2.19b (15-May-06), Copyright © 1994-2007 by
Samuel M. Goldwasser
Stormin Mormon
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"James H." <hall....@sbcglobal.net> wrote in message
news:i0rn7u$gb3$1...@speranza.aioe.org...
Harry K
> On Sun, 4 Jul 2010 22:15:32 -0700 (PDT), harry wrote:
> > IT sounds like the engine is unbalanced
>
> Yes. Something went unbalanced but I checked (visually only) the blade
> itself which seems to be all nicked up but no worse than it has been for a
> loooong time.
>
> > therefor some rotating part has broken off or the crankshaft is bent.
>
> It could be a bent crankshaft. I guess. But, I've hit far worse than what
> made this happen this time as it happened all of a sudden on me.
>
> How would I know if the crankshaft is bent?
>
Pull the plug (safety) and rotate the blade around: Measure clearance
between tip and housing at points 180 degrees apart. If same, not
bent. If different do the same check using the opposite end of the
blade for the measuring. If it is the same, i.e., diffenent 180
degrees apart and the difference is the same as your first check,
then the odds by far favor a bent shaft, not a bent blade. For
further proof put a new blade on and use that to check.
<snip remaining - answered down thread>
Harry K
James H.
> Does it run?
No. It won't start.
When I hit the obstruction, it stopped due to mechanical force I guess but
then it started running roughly like it was unbalanced. It almost sounded
like a multi-cylinder engine running on one cylinder - but I'm pretty sure
it's only a one-cylinder engine to start with so that's just what it
sounded like. Then, after a couple of minutes, it died and won't restart.
I've tried for a week to start it.
> If not the aluminum key was probably sheared, they are supposed to do
> that so the flywheel isn't damaged and it helps prevent bent crankshafts.
I see. Looking up "Lawn mower repair flywheel key replacement" I found a
video which, to my surprise, shows you have to get to that key from the
top. (I thought everything was accessed from the bottom business end of the
motor.)
> If it runs the blade was bent or a small piece of the blade broke
> off, the blade came loose(unlikely) the crankshaft was bent (I haven't
> seen that happen in a long time).
The blade isn't loose and it doesn't look bent. It's all dinged up but I've
had it for about 3 years and those dings started three years ago as the
soil is very rocky. About every 30 seconds I hear that hard crunch of
hitting the top of a rock. By now the rocks are mostly sheared down to the
grass level so that's why I was surprised that it stopped all of a sudden
on a pretty small rock, maybe six or eight inches in diameter that was
protroding up from the ground just above grass level in a relatively benign
rounded dome.
> We really need more details to help trouble shoot it. If it's running
> and the blade isn't bent it's possible the blade just needs sharpening
> and balancing.
I'll give you all the details you need. It's not running but I don't
"think" it's the ignition because it was directly related to hitting this
rock one too many times.
I'm googling for lawn mower repair and I see a few decent videos but none
yet for the Craftsman (I'll look up the model number in my paperwork and
report that if it helps.)
This video shows a briggs and stratten engine being repaired with just a
screwdriver and a hammer http://www.youtube.com/watch?v=vWcIiZtvbug
I'm looking for a Craftsman one as we speak.
James H.
> If you are lucky its a bent blade and sheared flywheel key, its a Diy
> job with a flywheel puller
I found a better video of a Craftsman with Tecumseh (I don't know what
engine I have yet) which used a flywheel puller to replace the keyway.
I was surprised there are no threaded holes for the flywheel puller, but
once you self-tap them, you pull it up (the other guy used a screwdriver
instead of a flywheel puller).
LSMFT
No mower is designed to mow rocks. I think they are just too lazy to
stop and remove the rock so it will never be an obstacle again.
Ledge rocks, it's quite obvious you need to go around.
--
LSmFT
I'm trying to think but nothing happens............
k...@att.bizzzzzzzzzzzz
wrote:
>On Mon, 05 Jul 2010 04:53:47 -0500, FatterDumber& Happier Moe wrote:
>
>> Does it run?
>No. It won't start.
>
>When I hit the obstruction, it stopped due to mechanical force I guess but
>then it started running roughly like it was unbalanced. It almost sounded
>like a multi-cylinder engine running on one cylinder - but I'm pretty sure
>it's only a one-cylinder engine to start with so that's just what it
>sounded like. Then, after a couple of minutes, it died and won't restart.
>I've tried for a week to start it.
Yep. Sounds like you ate the shear pin. This is a soft pin that holds the
flywheel onto the crank shaft. It's designed to shear and let the flywheel go
on its merry way so it doesn't bend the crank. Since the engine timing is
taken off the flywheel, the engine won't run after. When you hit the object
you probably broke the shear pin but didn't move the flywheel far enough, at
first, to keep the engine from running. However, it ran poorly because the
timing was off. After a little time unbalanced the flywheel moved further out
of place preventing it from running at all. With any luck, a $.25 shear pin
will get you back to the fun of mowing.
>> If not the aluminum key was probably sheared, they are supposed to do
>> that so the flywheel isn't damaged and it helps prevent bent crankshafts.
>I see. Looking up "Lawn mower repair flywheel key replacement" I found a
>video which, to my surprise, shows you have to get to that key from the
>top. (I thought everything was accessed from the bottom business end of the
>motor.)
>
>> If it runs the blade was bent or a small piece of the blade broke
>> off, the blade came loose(unlikely) the crankshaft was bent (I haven't
>> seen that happen in a long time).
>The blade isn't loose and it doesn't look bent. It's all dinged up but I've
>had it for about 3 years and those dings started three years ago as the
>soil is very rocky. About every 30 seconds I hear that hard crunch of
>hitting the top of a rock. By now the rocks are mostly sheared down to the
>grass level so that's why I was surprised that it stopped all of a sudden
>on a pretty small rock, maybe six or eight inches in diameter that was
>protroding up from the ground just above grass level in a relatively benign
>rounded dome.
>
>> We really need more details to help trouble shoot it. If it's running
>> and the blade isn't bent it's possible the blade just needs sharpening
>> and balancing.
>
>I'll give you all the details you need. It's not running but I don't
>"think" it's the ignition because it was directly related to hitting this
>rock one too many times.
The flywheel is part of the "ignition". The magneto is on the flywheel.
>I'm googling for lawn mower repair and I see a few decent videos but none
>yet for the Craftsman (I'll look up the model number in my paperwork and
>report that if it helps.)
Your Craftsman likely has either a Briggs or Techumseh engine. They're pretty
much all the same.
Joe
> What is the typical thing to look for that broke when my lawnmower hit a
> stationary object?
>
> I've hit much tougher sets of rocks than the little things that all of a
> sudden caused my Craftsman 18 inch push mower to wobble (I think) and run
> badly and now it won't start.
>
When you get your replacement mower, set the blade at 4" - 5" and get
comfortable with the idea that longer grass really looks better and
healthier. And every spring rake up all the rocks that popped up over
winter before you start mowing. That way you can save a lot of $$ and
time.
If you really like a lawn that shows white roots, see if a local goat
farmer will rent you one of his close grazers on occasion.
Joe
Nate Nagel
if it's got a Tecumseh engine, the normal consequence of hitting
something is that the flywheel key shears (it's designed to do that, to
protect the crank) and throws off the ignition timing. BTDT... the
fact that it ran rough and now won't start sounds very familiar... went
through this several times at a house I used to live in, yard was very
lumpy and if you didn't mow often enough you hit a couple stealth roots.
I could tell when I'd sheared the key by the mower starting to run
rough from the retarded ignition timing, but it'd run for a while until
I hit another root/rock/whatever and then I'd be done for.
the unbalance is likely due to a bent blade; if it's not, you've likely
bent the crank which means your mower is junk.
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
James H.
> When you hit the object you probably broke the shear pin but didn't
> move the flywheel far enough, at first, to keep the engine from running.
> However, it ran poorly because the timing was off. After a little time
> unbalanced the flywheel moved further out of place preventing it from
> running at all.
Now that makes sense! I remember now, that there was a lot of oil and smoke
too. I'll bet you're 100% right so I'll take it apart from the top and look
for that flywheel pin and report back to the team!
Harry K
The 'not starting' is almost assuredly a sheared pin. I worked for
part of year in my old man's fix-it shop. Overhauled one Briggs on a
tiller. Fired it up, ran good, next morning - no start. After a
couple hours fooling with it, I pulled the flywheel to find the key
only half shorn but it was enough to keep it from starting. It
probably was shorn when I shut it off the previous evening.
Yes, it is possible for it to have started with a partially shorn key
and then completed the shearing later.
Harry K
James H.
> On Mon, 5 Jul 2010 04:16:38 -0700 (PDT), ransley wrote:
>
> If you are lucky its a bent blade and sheared flywheel key,
> its a Diy job with a flywheel puller
It's a Briggs & Stratten 6.5 HP 21" cut Craftsman part number 917.388853
push mower. I found the manual here:
http://www.managemylife.com/mmh/lis_pdf/OWNM/L0505023.pdf
http://www.hammerwall.com/Download_Manual/14875/
http://tinyurl.com/32mzm2n
Interestingly, the owners manual says Sears doesn't recommend sharpening
the blade; I wonder why?
I checked the balance of the blade using the technique in the manual and it
seems to be balanced just fine (even though it's nicked up a bit).
This is the published procedure to check balance:
"NOTE: We do not recommend sharpening the blade - but if you do, be sure
the blade is balanced. To check blade balance, drive a nail into a beam or
wall. Leave about one inch of the straight nail exposed. Place center hole
of blade over the head of the nail. If blade is balanced, it should remain
in a horizontal position. If either end of the blade moves downward,
sharpen the heavy end until the blade is balanced."
James H.
> The 'not starting' is almost assuredly a sheared pin.
Hi Harry,
I suspect you are right.
I found the exploded diagrams for the Briggs & Stratton 6.5HP 21" push
mower (Sears catalogue number 917.388853) on http://searspartsdirect.com
But the weird thing is I can't find the "flywheel key" anywhere on the
exploded parts diagram.
There's just one big part (#59) called "Engine" which must contain the
sheared flywheel key; but I think I'll have to call Sears in the morning to
find the missing flywheel key. :(
If anyone looks at that http://searspartsdirect exploded diagram, do YOU
see the flywheel key?
James H.
> Shear key between flywheel and shaft.
> It's a Briggs & Stratten 6.5 HP 21" cut Craftsman part number 917.388853
> push mower. I found the manual here:
> http://www.managemylife.com/mmh/lis_pdf/OWNM/L0505023.pdf
> http://www.hammerwall.com/Download_Manual/14875/
> http://tinyurl.com/32mzm2n
From the owners manual, the engine of the Craftsman 917.388853 6.5HP 21"
push mower is a Briggs & Stratton, Model-Type-Trim of 123KO2-0444-E1.
Model = 123KO2
Type = 0444
Trim = E1
Looking at the web site for that Briggs & Stratton Model Number
123KO2-0444-E1 engine, I can't find the owners manual for the engine
itself.
http://www.briggsandstratton.com/maint_repair/manual_and_more/docsearch.aspx?enginelookfor=123KO2-0444-E1
I think I'll call Briggs & Stratton in the morning to find out WHY that
Model/Type/Trim combination isn't shown on their web site.
James H.
>> It's a Briggs & Stratten 6.5 HP 21" cut Craftsman part number 917.388853
>> http://www.hammerwall.com/Download_Manual/14875/
>> http://tinyurl.com/32mzm2n
>
> From the owners manual, the engine of the Craftsman 917.388853 6.5HP 21"
> push mower is a Briggs & Stratton, Model-Type-Trim of 123KO2-0444-E1.
I couldn't even find that model-type-trim on the Briggs and Stratton web
site ( http://www.briggsandstratton.com/maint_repair/manual_and_more ).
And, there was no exploded engine diagram on the Sears web site:
http://tinyurl.com/32mzm2n
Luckily, the downloaded manual contained, on page 36, an exploded diagram
of the engine.
http://www.managemylife.com/mmh/lis_pdf/OWNM/L0505023.pdf
Apparently the part I need from Sears or Briggs & Stratton is "#24" in the
center of the exploded engine diagram on page 36, part number 222698, name
= "key-flywheel".
I'll call Sears (800-488-1222) or Briggs & Stratton tomorrow during
business hours to see how to obtain this illusive flywheel key.
James H.
> No mower is designed to mow rocks.
The soil up here is so rocky that you can't help but hit little stones,
hundreds of them, every day. It just is. There's no way to get rid of them
because if you remove them, more take their place.
Based on all your help, I'm sure I sheared the $0.32 "key-flywheel" (Sears
P/N 222698) which I'll get from Sears or Briggs & Stratton tomorrow.
http://www.mfgsupply.com/SmEngEngineBSFly.html
Which is $3.32 (ten times that) at searspartsdirect:
http://tinyurl.com/2ulw53v
In the meantime, I'm looking up DIYs and found this good one:
http://www.ehow.com/how_4828024_replace-flywheel-key-briggs-stratton.html
http://www.youtube.com/watch?v=P-QINnsFYw0
Tony
You now must go to a Briggs online catalog. Sears doesn't list all the
engine parts because they don't make them. First search the engine for
the Briggs model and all other numbers with it. They often changed
parts during the run so those other numbers will get you to the proper
info. I think the numbers are normally stamped on the cowling part that
surrounds the flywheel.
Oren
<hall....@sbcglobal.net> wrote:
>
>Apparently the part I need from Sears or Briggs & Stratton is "#24" in the
>center of the exploded engine diagram on page 36, part number 222698, name
>= "key-flywheel".
You might want a couple of the flywheel shear keys. I've put a new
one in once, so if you're not careful and it slips a bit replacing the
flywheel the key will shear off again. Some keys will break completely
and others may just fracture slightly. A fractured one causes the
timing to be off, run bad and then break completely. The engine won't
run after is breaks.
I use a dab of bearing grease to hold the key (correct size key) in
place when putting the flywheel back on. It helps prevent it from
slipping. They can be tricky.
Looking at the crank in your link there is another key at the bottom
for the blade adapter (page 12* ). Hitting rock and roots, I'd expect
the blade adpter key to shear first, causing the blade to spin freely.
Unless that key is harder than the flywheel key -- I don't know.
Jules Richardson
> You now must go to a Briggs online catalog. Sears doesn't list all the
> engine parts because they don't make them. First search the engine for
> the Briggs model and all other numbers with it. They often changed
> parts during the run so those other numbers will get you to the proper
> info. I think the numbers are normally stamped on the cowling part that
> surrounds the flywheel.
Yes, all the B+S ones I've seen, it's stamped on the cowling, just above
the spark plug.
James H.
> On Tue, 06 Jul 2010 14:08:27 -0400, Tony wrote:
>> You now must go to a Briggs online catalog.
>
> it's stamped on the cowling, just above the spark plug.
Thanks.
I found the flywheel key parts diagram, luckily, in the downloaded manual
which contained, on page 36, an exploded diagram of the engine.
http://www.managemylife.com/mmh/lis_pdf/OWNM/L0505023.pdf
Apparently the part I need from Sears or Briggs & Stratton is "#24" in the
center of the exploded engine diagram on page 36, part number 222698, name
= "key-flywheel".
Looking it up, it apparently costs 32 cents.
James H.
> Looking at the crank in your link there is another key at the bottom
> for the blade adapter (page 12* ). Hitting rock and roots, I'd expect
> the blade adpter key to shear first, causing the blade to spin freely.
> Unless that key is harder than the flywheel key -- I don't know.
>
> http://www.managemylife.com/mmh/lis_pdf/OWNM/L0505023.pdf
Interesting. Thanks for pointing that out. I'm gonna have a look at that
mower again to see if that second key broke also.
James H.
> When you get your replacement mower
I may have to buy a new mower.
You guys were 100% right (that the flywheel key was broken); but the vidoes
on how to repair a briggs and stratton were ALL WRONG!
There is NO WAY you're gonna leverage the flywheel up. I tried, and I ended
up breaking a gas:air tube from the air filter. I'm not sure now if it's
worth repairing as multiple parts of plastic and aluminum are now broken.
For the record, the ONLY way to get that flywheel off is with a harmonic
balancer puller (an 8-inch gear puller failed to take it off). I still
don't have it off because I didn't have the right sized bolts for my
harmonic balancer puller ... but anyone who says you can leverage the
flywheel off with a screwdriver is mistaken.
I may need to buy a new lawnmower. :(
Judy Zappacosta
> There is NO WAY you're gonna leverage the flywheel up. I tried, and I ended
> up breaking a gas:air tube from the air filter. I'm not sure now if it's
> worth repairing as multiple parts of plastic and aluminum are now broken.
>
> For the record, the ONLY way to get that flywheel off is with a harmonic
> balancer puller (an 8-inch gear puller failed to take it off). I still
> don't have it off because I didn't have the right sized bolts for my
> harmonic balancer puller ...
I just found out the reasons my bolts didn't fit was the fact that you need
special self-tapping bolts!
According to this web site, I need self-tapping bolts. But who has these
and what size?
___ ___
|___| |___|<-------- Self tapping bolts or pretap holes.
| | | |
_|-|_ _|-|_
| |-| | | |-| |<------- Tighten nuts to release flywheel.
___|_|-|_|__________|_|-|_|___
| |-| |-| |<--- Plate or block - 1/4" or thicker steel
|_____|-|______________|-|_____|
|-| .-.----.-. |-|
|-| | :----: |<-|-|---------- Flywheel nut - loosen slightly.
|-| |_:----:_| |-|
______|-|___ :----: ___|-|______
//////:-:///|:----:|///:-://////
//////:-:///|:----:|///:-:////// <-- Flywheel comes with predrilled
holes.
//////'-'///|:----:|///'-'////// (taper not shown - ASCII
limitations!)
//////| |///|:----:|///| |//////
JIMMIE
> What is the typical thing to look for that broke when my lawnmower hit a
> stationary object?
>
> I've hit much tougher sets of rocks than the little things that all of a
> sudden caused my Craftsman 18 inch push mower to wobble (I think) and run
> badly and now it won't start.
>
> person probably will only charge half the cost of a new one.
>
> But, I wonder if I take it apart, what would I be looking for?
>
> I've never taken a lawn mower apart but I've fixed things and have all the
> mechanics tools for my car, for example, and a lawn mower can't possibly be
> too complicated.
>
> What would I be looking for. What is the typical thing that breaks when a
> lawnmower hits an immovable object?
Sounds like the shear key on the flywheel may have sheared.. This will
put the timing off. Also check for damed blade . After this we are
talking crankshaft damage... I this is the case it is not worth
fixing.
Jimmie
Eric in North TX
I've never had any trouble removing one, trick is; you don't pry it
off, you just put tension on it so when you smack the crankshaft with
a hammer, the crankshaft slips through it releasing the taper. It is
one of those things that once you do it you see how easy it was, but
before that seems impossible.
Harry K
What Eric said but to explain it a bit more: Lever pressure on the
screwdriver and smack the NUT on the crankshaft. That nut needs to be
loose with no crankshaft threads showing above it.
I am a member in the church of "a BFH will fix most anything"
Give it a try on your junker.
Harry K
Oren
>On Mon, 5 Jul 2010 11:19:20 -0700 (PDT), Joe wrote:
>> When you get your replacement mower
>
>I may have to buy a new mower.
>
>You guys were 100% right (that the flywheel key was broken); but the vidoes
>on how to repair a briggs and stratton were ALL WRONG!
>
>There is NO WAY you're gonna leverage the flywheel up. I tried, and I ended
>up breaking a gas:air tube from the air filter. I'm not sure now if it's
>worth repairing as multiple parts of plastic and aluminum are now broken.
>
Did you pry up or down with the screwdriver?
>For the record, the ONLY way to get that flywheel off is with a harmonic
>balancer puller (an 8-inch gear puller failed to take it off). I still
>don't have it off because I didn't have the right sized bolts for my
>harmonic balancer puller ... but anyone who says you can leverage the
>flywheel off with a screwdriver is mistaken.
>
No. What Eric and Harry K said is correct. Growing up, tinkering with
mowers I never used (or knew) a puller..
Loosen the nut up to the top of the crank -- do not remove it and make
sure the threads are below the nut. Never hit the crank with a hammer,
with the nut completely removed. That will cause thread damage and you
cannot thread the nut back on.
Position the screwdriver under the flywheel 180° opposite the flywheel
key way, pry up with the screwdriver and smack the nut with the
hammer. It may pop the first time or need a couple more smacks. Even
adding a penetrating oil around the key way/crank will help.
Stormin Mormon
off tool, and big hammer.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
James H.
> Big screw driver to pull up. Knock off tool to protect the shaft. And
> then apply BFH. Works, fine.
I don't understand the "knock off tool". I bought one. But for two reasons,
I will return it.
The first reason isn't the tool's fault (it was the wrong size); but even
so, how does banging on the crankshaft (and lifting underneath with a pry
bar) magically free up the flywheel?
Of course, lifting up on the flywheel with a prybar, is applying force to
free it up; but how is whacking the crankshaft applying ANY force
whatsoever in the direction we want the flywheel to go (which is up)?
James H.
> Sounds like the shear key on the flywheel may have sheared..
> This will put the timing off.
That's exactly what happened. The flywheel "pin" was shaped like a Z (side
view) instead of a rectangle (I bought six new Briggs and Stratton flywheel
keys from Ace hardware and none look like a Z from the side.)
The hard part wasn't getting the flywheel off; it was figuring HOW to get
the flywheel off. Banging on the crankshaft and prying up on the flywheel
only served to break the plastic intake manifold in half, bending one of
its bolts and breaking the other one in half.
Success only came to me after I totally gave up on this crazy
bang-on-the-crankshaft-and-pry-the-flywheel method. When I finally realized
there were two untapped holes for a harmonic balancer puller, I simply
tapped them with a 1/4 x 20 tap, and voila! The flywheel pulled off with
ease using the flywheel puller.
Now I have to order a new plastic intake manifold, and pick up a set of
screw extractors to extract the broken intake-manifold bolt.
In hind sight, if you have a Briggs and Stratton engine (specifically the
Briggs and Stratton 123K02-0444-E1 engine), DO NOT pry up on the flywheel
and bang down on the crankshaft (what's that gonna do anyway, beside break
stuff). There's NOWHERE to pry except soft aluminum and plastic anyway.
Just use a harmonic balancer puller (after tapping the holes in the
flywheel left for this purpose). I wish I knew that when I started this
thread! :)
I do THANK EVERYONE for all your help; it was my first lawnmower repair in
my life! When the parts come in for the broken intake manifold, I hope it
will work again!
James H.
> Now I have to order a new plastic intake manifold, and pick up a set of
> screw extractors to extract the broken intake-manifold bolt.
I ordered a new intake manifold, busted when I followed the errant advice
to bang on the crankshaft and pry up on the flywheel.
Don't bang and pry!
Nothing is gonna happen except aluminum and plastic stuff under the engine
will break. The plastic part that broke is #50 (intake manifold, Sears PN
497465) and #54 (intake manifold screw) on page 36 of this 40-page pdf.
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, we'll put it all back together (with the
new crankshaft pin) and cross our fingers.
Thanks for all your advice; you guys are wonderful!
Stormin Mormon
the same as moving the flywheel up. Mostly just shears the friction
fit from the flywheel to the crankshaft. Try it... worked for many men
on many occasions.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"James H." <hall....@sbcglobal.net> wrote in message
news:i18up9$mft$1...@speranza.aioe.org...
Stormin Mormon
mentor to show you the technique.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"James H." <hall....@sbcglobal.net> wrote in message
news:i190k3$occ$1...@speranza.aioe.org...
Eric in North TX
http://www.youtube.com/watch?v=Plktb3a_-MI
Around 4.01 he taps it off, he doesn't even bother with the prybar.
Eric in North TX
> On Sat, 10 Jul 2010 12:08:38 -0700 (PDT), Eric in North TX
>
> <tine...@gmail.com> wrote:
>
> >http://www.youtube.com/watch?v=Plktb3a_-MI
> >Around 4.01 he taps it off, he doesn't even bother with the prybar.
>
Based on what? I've never seen one put up that little fight, but am
open to the possibility.
Perhaps that Canuk has talent.
Tapers are as much VooDoo as skill, I've seen really capable people
walk up and drop a tie-rod or ball joint & even a small engine
flywheel with a flick of the wrist, that someone else has been slaving
over for hours.
Oren
>http://www.youtube.com/watch?v=Plktb3a_-MI
>Around 4.01 he taps it off, he doesn't even bother with the prybar.
At 4:02 he points out that there are no holes for a "puller".
Oren
<tin...@gmail.com> wrote:
>> >http://www.youtube.com/watch?v=Plktb3a_-MI
>> >Around 4.01 he taps it off, he doesn't even bother with the prybar.
>>
>> Apparently you've never taken a flywheel off.
>
>Based on what? I've never seen one put up that little fight, but am
>open to the possibility.
>Perhaps that Canuk has talent.
IME, it came off easy, because it is a horizontal crank _and_ the
shear key was not sheared (you can still see in the crank key way).
When the key shears it binds the flywheel and crank shaft. IOW,
harder to get off for those without a "puller". It can be done.
Once I popped a flywheel on a vertical shaft: placed a 2 ba fer on the
nut and whacked it with a hammer.
Stormin Mormon
speciality items are sold. And the process is reccomended by folks who
know.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"WaIIy" <WaIIy@(nft).invalid> wrote in message
news:3obh369iiatndjth1...@4ax.com...
Only a hammer mechanic uses that method.
Maybe you can patent it and call it the "Budweiser method".
Jerry - OHIO
childs play.
Jr.
Hustlin' Hank
<cayoung61**spambloc...@hotmail.com> wrote:
but how is whacking the crankshaft applying ANY force
> whatsoever in the direction we want the flywheel to go (which is up)?
Pretty much the same way an impact driver works. Also, if you have
loosened any bolts/nuts, you know that just pulling on a wrench is
much harder than hitting the wrench slightly with your palm is much
easier and less busted knuckels. Basically the same principle.
I could explain the physics if needed, but I think you get the point.
Hank <~~~too lazy to write a dissertation
James H.
> I can do a steering wheel on a car with one hit. A mower flywheel is
> childs play.
In the end, the flywheel was easy to get off once I 1/4x20 tapped the two
holes drilled for that purpose but never tapped by the manufacturer and
then used a harmonic balancer puller which lifted it right off in seconds.
One thing I just don't understand though.
How is hitting DOWN on the CRANKSHAFT supposed to free the flywheel in the
bang-and-lift method?
Can someone explain the logic of banging on the crankshaft to remove the
flywheel?
Eric in North TX
I'll try (sigh) There is some end play in the crank whether you can
feel it or not. The lift with the prybar / screwdriver, takes that up,
the hammer blow drives the crankshaft down, while the lift holds the
flywheel up causing the crankshaft to move through the flywheel. The
hammer blow needs to be quick rather than hard.
Steve Barker
what you do is stick a pry bar UNDER the flywheel, then with the nut
started on the crankshaft (to protect the threads) you sharply rap the
crank and the flywheel will pop right off. Basically, you are using the
(very small) amount of crankshaft end play as your movement. Those holes
were not tapped, because that is not what they are for.
--
Steve Barker
remove the "not" from my address to email
James H.
> What is the typical thing to look for that broke when my lawnmower hit a
> stationary object?
Thanks to all your help, you guys enabled me to figure out what the problem
was.
As you all said, it was the flywheel key.
Here are pictures of the job. I learned a lot. What's important to tell
others is that the "traditional" brute-force method of removing a flywheel
is only for experts and even then, only for people working on other
people's mowers! :)
See details here:
Direct Link: http://img251.imageshack.us/g/image001ol.jpg/
Short Link: http://yfrog.com/6zimage001oljx
Web Player:
http://img251.imageshack.us/slideshow/webplayer.php?id=image001ol.jpg
ransley
Flywheels are balanced, I have one balanced with a weight on a boat
motor, I hope it runs ok because drilling it changed the balance. I
had a flywheel on a boat motor that was so tough to remove it took
days and ruined - bent, one puller. I can see how it could be hard to
remove but it takes practice and maybe a special tool since it had no
holes.
m6onz5a
>
> - Show quoted text -
m6onz5a
First check for a bent blade. If you replace the blade & it still
shakes/wobbles you bent the crank.
mkir...@rochester.rr.com
> others is that the "traditional" brute-force method of removing a flywheel
> is only for experts and even then, only for people working on other
> people's mowers! :)
No.
What's important is to tell others that engine work is too complicated
for morons who didn't pay attention in 7th grade physical science
class.
James H.
> Flywheels are balanced ...
Hi Ransley,
I updated the pictures to show the flywheel holes.
http://img708.imageshack.us/g/briggsandstrattonflywhe.jpg/
http://yfrog.com/jobriggsandstrattonflywhej
http://img708.imageshack.us/img708/7369/briggsandstrattonflywhe
I hope tapping them didn't change the balance as that's all that is
required. Do you think merely tapping the two holes changes the balance?
It's the proper way to remove this flywheel (I now know).
Once cleaned (and chalked), you can see in the pictures the Briggs and
Stratton flywheel says "TO REMOVE, USE WHEEL PULLER HOLES", and then it has
two big arrows pointing to the two untapped holes.
So, the instructions I was given to bang and pry were wrong, at least
they're wrong in two ways:
1. It's definitely not the manufacture's documented method
2. It's not for someone with zero experience (such as I am).
This video shows the (wrong) traditional method:
http://www.waldeneffect.org/blog/Briggs_and_Stratton_flywheel_removal/
So, I'm posting here to help the next homeowner. The proper way to remove
THIS Briggs & Stratton flywheel is:
1. Tap the two pre-drilled holes (1/4 x 20)
2. Pull up with a BS 19069 flywheel puller (available as a harmonic
balancer puller at any auto parts store)
The owners manual (page 38 & 39) show this as Sears P/N: 19069:
http://www.google.com/url?sa=D&q=http://www.managemylife.com/mmh/lis_pdf/OWNM/L0505023.pdf&usg=AFQjCNH2N8YjjLyskja0QyfRWxQAo5_C_A
This is the $7.50 flywheel puller (Briggs & Stratton P/N: BS 19069):
http://farmex.now.tc/catalog/product_info.php?products_id=2368
http://tewarehouse.com/7-05979
http://www.jackssmallengines.com/service_tools2.cfm
Briggs & Stratton FAQs say to use the flywheel puller:
http://engines.myfaqcenter.com/Answer.aspx?p_faqid=3422
This says it's dangerous (to the equipment) to smack the crankshaft.
http://outdoorpowerinfo.com/repairs/flywheel_removal.asp
This says the same thing:
http://www.repairfaq.org/samnew/lmfaq/lmflyrml.htm
This also says to use the flywheel puller:
http://www.ehow.com/way_5655790_briggs-stratton-flywheel-removal.html
So, I now know the answer but I want the next guy who runs across this
advice to get the right advice; otherwise they'll end up breaking more than
they repair just as I did by using the wrong method and the wrong tools in
the wrong way to remove a Briggs & Stratton flywheel.
Thansk everyone! I hope this helps others.
James H.
> First check for a bent blade. If you replace the blade & it still
> shakes/wobbles you bent the crank.
Thanks for that advice. I don't see a wobble in the blade but I did order a
new blade and I'll report back whether or not the crankshaft is bent.
I'll measure the distance from the blade to the ground in the East-West
position and then in the North-South position.
If it's off, I'll buy a new crankshaft and put it in if I can. That would
be a whole new set of pictures! :)
http://img708.imageshack.us/g/briggsandstrattonflywhe.jpg/
http://yfrog.com/jobriggsandstrattonflywhej
http://img708.imageshack.us/img708/7369/briggsandstrattonflywhe.jpg
James H.
> What's important is to tell others that engine work is too complicated
> for morons
While using the brute-force method of removing a flywheel works:
http://www.waldeneffect.org/blog/Briggs_and_Stratton_flywheel_removal/
The proper way to remove this type of Briggs & Stratton flywheel is to tap
the holes and use a Briggs & Stratton BS 19069 flywheel puller (also
available as a harmonic balancer puller at any auto parts store).
You can see the words saying so right on the flywheel (once cleaned &
chalked) in these photos of the job (and destruction) I took:
http://img708.imageshack.us/g/briggsandstrattonflywhe.jpg/
http://yfrog.com/jobriggsandstrattonflywhej
http://img708.imageshack.us/img708/7369/briggsandstrattonflywhe.jpg
The Briggs & Stratton FAQ says to tap the holes with a 1/4 x 20 tap:
http://engines.myfaqcenter.com/Answer.aspx?p_faqid=3422
http://www.briggsracing.com/en/articles/tool-of-the-month/using-flywheel-puller.aspx
Other articles say to tap the holes and use the flywheel puller:
http://outdoorpowerinfo.com/repairs/flywheel_removal.asp
http://www.repairfaq.org/samnew/lmfaq/lmflyrml.htm
http://www.ehow.com/way_5655790_briggs-stratton-flywheel-removal.html
This is the $7.50 flywheel puller (Briggs & Stratton P/N: BS 19069):
http://farmex.now.tc/catalog/product_info.php?products_id=2368
http://tewarehouse.com/7-05979
http://www.jackssmallengines.com/service_tools2.cfm
The owners manual (page 38 & 39) show this as Sears P/N: 19069:
http://www.google.com/url?sa=D&q=http://www.managemylife.com/mmh/lis_pdf/OWNM/L0505023.pdf&usg=AFQjCNH2N8YjjLyskja0QyfRWxQAo5_C_A
Net result:
1. Do not pry and bang
2. You must tap and pull
Oren
<hall....@sbcglobal.net> wrote:
>On Tue, 13 Jul 2010 07:01:08 -0700 (PDT), m6onz5a wrote:
>> First check for a bent blade. If you replace the blade & it still
>> shakes/wobbles you bent the crank.
>
>Thanks for that advice. I don't see a wobble in the blade but I did order a
>new blade and I'll report back whether or not the crankshaft is bent.
>
>I'll measure the distance from the blade to the ground in the East-West
>position and then in the North-South position.
>
>If it's off, I'll buy a new crankshaft and put it in if I can. That would
>be a whole new set of pictures! :)
Caution: Replacing the crankshaft may require the judicial use of a
pry bar and a hammer. You have been warned.
If you bent the crank, go buy a new mower for 200 bucks.
Bob F
> Net result:
> 1. Do not pry and bang
> 2. You must tap and pull
That would be "you", not me.
Brent
I have an old mower which might have the same problem.
I read some of the references and noticed the ones that compared the two
methods always suggested the contraption to pull the flywheel up.
Does anyone know of a reference that actually compares the two methods and
still recommends the sharp tap with a hammer over the use of the special
tool?
TITLE: Flywheel Removal - The Right Way and Several Wrong Ways
QUOTE: "The best technique requires a special tool - a flywheel puller; the
least preferred method requires nothing more than a hammer and a
screwdriver, but can easily result in serious damage to the flywheel and or
crankshaft."
TITLE: http://www.repairfaq.org/samnew/lmfaq/lmflyrml.htm
QUOTE: "There are several approaches to flywheel removal. The best way by
far is to use a special puller designed for your particular engine. Briggs
& Stratton and Tecumseh flywheels usually have 2 or 3 holes placed around
the center of the flywheel which are used with special puller blocks. These
have self tapping bolts which you thread into the holes and then tighten
down nuts to pop the flywheel off of the crankshaft."
Brent
> TITLE: Flywheel Removal - The Right Way and Several Wrong Ways
Ops. I forgot to list the reference for the first quote comparing the
methods and concluding the special tool was the preferred method.
http://outdoorpowerinfo.com/repairs/flywheel_removal.asp
The second quote came from here.
http://www.repairfaq.org/samnew/lmfaq/lmflyrml.htm
Both compared the two methods and concluded the special tool was safer.
Do you know of any reference that compares both methods yet still
recommends the hammer and screwdriver method over the puller method?
Oren
<beemd...@Use-Author-Supplied-Address.invalid> wrote:
>Both compared the two methods and concluded the special tool was safer.
Golly gee. We all know the hammer is last resort. Some flywheels
don't have holes for a puller. Using the wrong "special tool" as the
OP -- you can fracture the flywheel. He bent his flywheel... he saw it
"bend".
>
>Do you know of any reference that compares both methods yet still
>recommends the hammer and screwdriver method over the puller method?
Tradition, I say!
My best reference was my grandfather. I was knee-high to a grass
hopper. Off the frame, he picked the engine up by the flywheel (nut
positioned at the top). Not far from the ground he smacked the
crank... remove nut and go to work.
Sorry I didn't keep a journal
jim
Brent wrote:
>
> On Tue, 13 Jul 2010 14:36:59 -0700, Bob F wrote:
>
> >> Net result:
> >> 1. Do not pry and bang
> >> 2. You must tap and pull
> > That would be "you", not me.
>
> I have an old mower which might have the same problem.
You don't have to take the flywheel off to determine if the key is
sheared. Just remove the retaining nut and look at the key. If it isn't
sheared no need to take off the flywheel.
-jim
Oren
wrote:
>> I have an old mower which might have the same problem.
>
>You don't have to take the flywheel off to determine if the key is
>sheared. Just remove the retaining nut and look at the key. If it isn't
>sheared no need to take off the flywheel.
No but looking at the shear key under the nut will not tell you if the
key fractured midway in the crank key way.
Some keys don't snap or look obvious. The engine will misfire.
Harry K
Yep, BTDT and have the t-shirt. Took me a full day fooling with it
before I finally pulled the flywheel and saw the half-sheared key.
Harry K
jim
If you can't tell if the flywheel and shaft keyways are aligned, then
maybe a visit to the optometrist will help.
I don't even use a key. Just line up the two key slots and tighten the
nut. Eliminating the jammed key makes it easier to remove if you hit
something, also.
-jim