21" Yard Machines push mower with 4.5 hp Briggs/Stratton Quattro, about 12
years old.

Yesterday I pulled/sharpened the blade, cleaned the air filter, and changed
the oil. Old oil looked about the same as always after 1 full season.

Today I start it up, I get a CLANK-CLANK-CLANK proportional to rpm, and kinda
like a rod knockin'. Gets lots worse as I try to mow, so I stop and test. The
motor will turn over and start with the rip-cord, but it feels t-i-g-h-t. Oil
is clean and up-to-level.

Definitely a candidate for the junkyard, but ... what happened? Key sheared
off the flywheel??

P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

Puddin' Man wrote:
21" Yard Machines push mower with 4.5 hp Briggs/Stratton Quattro,
about 12 years old.

Yesterday I pulled/sharpened the blade, cleaned the air filter, and
changed the oil. Old oil looked about the same as always after 1 full
season.

Today I start it up, I get a CLANK-CLANK-CLANK proportional to rpm,
and kinda like a rod knockin'. Gets lots worse as I try to mow, so I
stop and test. The motor will turn over and start with the rip-cord,
but it feels t-i-g-h-t. Oil is clean and up-to-level.

Definitely a candidate for the junkyard, but ... what happened? Key
sheared off the flywheel??


I'll bet the problem is centered on the blade you removed/replaced.

Is is balanced? On upside down? Hitting something?

On Sat, 16 Oct 2010 17:49:58 -0500, Puddin' Man
wrote:


21" Yard Machines push mower with 4.5 hp Briggs/Stratton Quattro, about 12
years old.

Yesterday I pulled/sharpened the blade, cleaned the air filter, and changed
the oil. Old oil looked about the same as always after 1 full season.

Today I start it up, I get a CLANK-CLANK-CLANK proportional to rpm, and kinda
like a rod knockin'. Gets lots worse as I try to mow, so I stop and test. The
motor will turn over and start with the rip-cord, but it feels t-i-g-h-t. Oil
is clean and up-to-level.

Definitely a candidate for the junkyard, but ... what happened? Key sheared
off the flywheel??


If the engine runs with any reasonable expectation -- my guess it is
not a shear pin/key that has broken.

If this started after you worked on the blade, go back and look.
Follow the problem backwards.

Got any barbed wire/string caught around the shaft?

Well, a couple things come to mind.

Blade may be loose -- the engine relies on the "flywheel effect" of
the blade to keep the crankshaft turning.

Please double check that you added the correct ammount of oil.
Probably about 20 ounces.

As others have written, please check to see if something is tangled
in, or hitting the blade.

If the mower has a "safety handle", please check to see if the safety
brake is fully releasing. Could explain the tight feel.

Might not be an issue. But, pull the spark plug out. Then yank the rip
cord a couple times. Sometimes oil gets in the cylinder. With the plug
out, the oil will spray out when you pull the starter cord. I've seen
oil or gasoline in the cylinder, after a mower is tipped on its side.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Puddin' Man" wrote in message
...

21" Yard Machines push mower with 4.5 hp Briggs/Stratton Quattro,
about 12
years old.

Yesterday I pulled/sharpened the blade, cleaned the air filter, and
changed
the oil. Old oil looked about the same as always after 1 full season.

Today I start it up, I get a CLANK-CLANK-CLANK proportional to rpm,
and kinda
like a rod knockin'. Gets lots worse as I try to mow, so I stop and
test. The
motor will turn over and start with the rip-cord, but it feels
t-i-g-h-t. Oil
is clean and up-to-level.

Definitely a candidate for the junkyard, but ... what happened? Key
sheared
off the flywheel??

P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

On Oct 16, 3:49*pm, Puddin' Man wrote:
21" Yard Machines push mower with 4.5 hp Briggs/Stratton Quattro, about 12
years old.

Yesterday I pulled/sharpened the blade, cleaned the air filter, and changed
the oil. Old oil looked about the same as always after 1 full season.

Today I start it up, I get a CLANK-CLANK-CLANK proportional to rpm, and kinda
like a rod knockin'. Gets lots worse as I try to mow, so I stop and test. The
motor will turn over and start with the rip-cord, but it feels t-i-g-h-t. Oil
is clean and up-to-level.

Definitely a candidate for the junkyard, but ... what happened? Key sheared
off the flywheel??

* P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

This is probably not related to your problem but does your lawn mower
have a fuel filter? I also have a Briggs and Stratton and didn’t know
it didn't have a fuel filter until I had to take it apart recently. I
had to buy an in line fuel filter an put it in the fuel line because
the gas tank seal and fuel hose were disintegrating.

Puddin' Man wrote:

21" Yard Machines push mower with 4.5 hp Briggs/Stratton Quattro, about 12
years old.

Yesterday I pulled/sharpened the blade, cleaned the air filter, and changed
the oil. Old oil looked about the same as always after 1 full season.

Today I start it up, I get a CLANK-CLANK-CLANK proportional to rpm, and kinda
like a rod knockin'. Gets lots worse as I try to mow, so I stop and test. The
motor will turn over and start with the rip-cord, but it feels t-i-g-h-t. Oil
is clean and up-to-level.

Definitely a candidate for the junkyard, but ... what happened? Key sheared
off the flywheel??

P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

Look out, the rod is ready to come out the bottom of the crank case.

--
LSMFT

Simple job, assist the assistant of the physicist.

On Oct 16, 9:41*pm, LSMFT wrote:
Puddin' Man wrote:

21" Yard Machines push mower with 4.5 hp Briggs/Stratton Quattro, about 12
years old.

Yesterday I pulled/sharpened the blade, cleaned the air filter, and changed
the oil. Old oil looked about the same as always after 1 full season.

Today I start it up, I get a CLANK-CLANK-CLANK proportional to rpm, and kinda
like a rod knockin'. Gets lots worse as I try to mow, so I stop and test. The
motor will turn over and start with the rip-cord, but it feels t-i-g-h-t. Oil
is clean and up-to-level.

Definitely a candidate for the junkyard, but ... what happened? Key sheared
off the flywheel??

* *P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

Look out, the rod is ready to come out the bottom of the crank case.

--
LSMFT

Simple job, assist the assistant of the physicist.- Hide quoted text -

- Show quoted text -

If it is a vertical shaft lawnmower, the rod, assuming you mean the
connecting rod, will come out the side of the engine, not the bottom.
You are exposing your lack of knowledge of lawnmower engines.

On Sat, 16 Oct 2010 19:37:27 -0700 (PDT), Molly Brown
wrote:

This is probably not related to your problem but does your lawn mower
have a fuel filter? I also have a Briggs and Stratton and didn’t know
it didn't have a fuel filter until I had to take it apart recently. I
had to buy an in line fuel filter an put it in the fuel line because
the gas tank seal and fuel hose were disintegrating.

Right. The OP has a "CLANK-CLANK-CLANK proportional to rpm..."

Nuttin to do with fuel.

Now if he ran over a cow bell, I could be wrong.

On Sat, 16 Oct 2010 22:41:51 -0400, LSMFT wrote:

Look out, the rod is ready to come out the bottom of the crank case.

Rods throw out the thin sides of an engine, not a bottom of an engine
block.

If the rod journal stays attached on the crank, breaks, a portion of
the rod is slung to the side.

Stormin Mormon wrote:

Well, a couple things come to mind.

Blade may be loose -- the engine relies on the "flywheel effect" of
the blade to keep the crankshaft turning.

Please double check that you added the correct ammount of oil.
Probably about 20 ounces.

As others have written, please check to see if something is tangled
in, or hitting the blade.

If the mower has a "safety handle", please check to see if the safety
brake is fully releasing. Could explain the tight feel.

Might not be an issue. But, pull the spark plug out. Then yank the rip
cord a couple times. Sometimes oil gets in the cylinder. With the plug
out, the oil will spray out when you pull the starter cord. I've seen
oil or gasoline in the cylinder, after a mower is tipped on its side.



How long would you expect that oil to stay in the cylinder when he had
the engine RUNNING?

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10e12 furlongs per fortnight.

"Molly Brown" wrote in message
...
On Oct 16, 3:49 pm, Puddin' Man wrote:
21" Yard Machines push mower with 4.5 hp Briggs/Stratton Quattro, about
12
years old.

Yesterday I pulled/sharpened the blade, cleaned the air filter, and
changed
the oil. Old oil looked about the same as always after 1 full season.

Today I start it up, I get a CLANK-CLANK-CLANK proportional to rpm, and
kinda
like a rod knockin'. Gets lots worse as I try to mow, so I stop and test.
The
motor will turn over and start with the rip-cord, but it feels t-i-g-h-t.
Oil
is clean and up-to-level.

Definitely a candidate for the junkyard, but ... what happened? Key
sheared
off the flywheel??

P

Sounds like more than likely when you installed the blade, it wasn't
properly
centered and is hitting the underside of the deck.

Bob-tx

On Sat, 16 Oct 2010 17:49:58 -0500, Puddin' Man wrote:
Definitely a candidate for the junkyard

I'm not sure if that's sound logic... :-)

but ... what happened? Key sheared off the flywheel??

Others have mentioned a blade issue, but also is there a chance you've
broken or bent something at the top of the engine while you were working
on the underside? Maybe an engine cowl or something like that?

(anyone know if these smaller B+S engines have a vane governor, or do
they have a mechanical governor in the sump and driven off the cam, like
the larger B+S engines do?)

cheers

Jules

hr(bob) wrote:
On Oct 16, 9:41 pm, wrote:
Puddin' Man wrote:

21" Yard Machines push mower with 4.5 hp Briggs/Stratton Quattro, about 12
years old.

Yesterday I pulled/sharpened the blade, cleaned the air filter, and changed
the oil. Old oil looked about the same as always after 1 full season.

Today I start it up, I get a CLANK-CLANK-CLANK proportional to rpm, and kinda
like a rod knockin'. Gets lots worse as I try to mow, so I stop and test. The
motor will turn over and start with the rip-cord, but it feels t-i-g-h-t. Oil
is clean and up-to-level.

Definitely a candidate for the junkyard, but ... what happened? Key sheared
off the flywheel??

P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

Look out, the rod is ready to come out the bottom of the crank case.

--
LSMFT

Simple job, assist the assistant of the physicist.- Hide quoted text -

- Show quoted text -

If it is a vertical shaft lawnmower, the rod, assuming you mean the
connecting rod, will come out the side of the engine, not the bottom.
You are exposing your lack of knowledge of lawnmower engines.

The bottom is usually facing the rear on a single cylinder vertical.
You just don't know what the bottom is, your ignorance.

--
LSMFT

Simple job, assist the assistant of the physicist.

On Mon, 18 Oct 2010 18:16:38 -0400, LSMFT wrote:

hr(bob) wrote:
On Oct 16, 9:41 pm, wrote:
Puddin' Man wrote:

21" Yard Machines push mower with 4.5 hp Briggs/Stratton Quattro,
about 12 years old.

Yesterday I pulled/sharpened the blade, cleaned the air filter, and
changed the oil. Old oil looked about the same as always after 1 full
season.

Today I start it up, I get a CLANK-CLANK-CLANK proportional to rpm,
and kinda like a rod knockin'. Gets lots worse as I try to mow, so I
stop and test. The motor will turn over and start with the rip-cord,
but it feels t-i-g-h-t. Oil is clean and up-to-level.

Definitely a candidate for the junkyard, but ... what happened? Key
sheared off the flywheel??

P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

Look out, the rod is ready to come out the bottom of the crank case.

--
LSMFT

Simple job, assist the assistant of the physicist.- Hide quoted text -

- Show quoted text -

If it is a vertical shaft lawnmower, the rod, assuming you mean the
connecting rod, will come out the side of the engine, not the bottom.
You are exposing your lack of knowledge of lawnmower engines.

The bottom is usually facing the rear on a single cylinder vertical. You
just don't know what the bottom is, your ignorance.

Isn't that an end, rather than a bottom? :-)

I've just been soak-testing my spare vertical-shaft B+S engine after
patching up its damaged cylinder bore - the darn thing made me rather
nervous, particularly when tuning the carb, as I wasn't 100% confident
that it was going to hold together.

Give me a horizontal-shaft engine any day, as at least it's generally
possible to stand close to it somewhere where you aren't going to get hit
in the shins if it goes bang :-)

cheers

Jules

On Sat, 16 Oct 2010 18:21:58 -0500, "HeyBub" wrote:

I'll bet the problem is centered on the blade you removed/replaced.

Is is balanced? On upside down? Hitting something?

Mea Culpa!

I hadda lock washer on the blade bolt. Torqued the hull outa it.
Checked it when the problem first arose. Looked OK.

But it weren't. Blade rattled loose again. Sounded damned funny
for a loose blade, too.

Thanks,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

On Mon, 18 Oct 2010 18:07:27 -0500, Puddin' Man
wrote:

On Sat, 16 Oct 2010 18:21:58 -0500, "HeyBub" wrote:

I'll bet the problem is centered on the blade you removed/replaced.

Is is balanced? On upside down? Hitting something?

Mea Culpa!

I hadda lock washer on the blade bolt. Torqued the hull outa it.
Checked it when the problem first arose. Looked OK.

But it weren't. Blade rattled loose again. Sounded damned funny
for a loose blade, too.

That sure will cause the "CLANK-CLANK-CLANK proportional to rpm..."
grin

Glad you found it and the blade stayed on the shaft, saving a foot.

On Mon, 18 Oct 2010 18:16:38 -0400, LSMFT wrote:

hr(bob) wrote:
On Oct 16, 9:41 pm, wrote:
Puddin' Man wrote:

21" Yard Machines push mower with 4.5 hp Briggs/Stratton Quattro, about 12
years old.

Yesterday I pulled/sharpened the blade, cleaned the air filter, and changed
the oil. Old oil looked about the same as always after 1 full season.

Today I start it up, I get a CLANK-CLANK-CLANK proportional to rpm, and kinda
like a rod knockin'. Gets lots worse as I try to mow, so I stop and test. The
motor will turn over and start with the rip-cord, but it feels t-i-g-h-t. Oil
is clean and up-to-level.

Definitely a candidate for the junkyard, but ... what happened? Key sheared
off the flywheel??

P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

Look out, the rod is ready to come out the bottom of the crank case.

--
LSMFT

Simple job, assist the assistant of the physicist.- Hide quoted text -

- Show quoted text -

If it is a vertical shaft lawnmower, the rod, assuming you mean the
connecting rod, will come out the side of the engine, not the bottom.
You are exposing your lack of knowledge of lawnmower engines.

The bottom is usually facing the rear on a single cylinder vertical.
You just don't know what the bottom is, your ignorance.
And it is MUCH more likely to come out the side than the bottom or
back, regardless which way the shaft is oriented.

Oh, it varies. Depending on how much oil.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"jeff_wisnia" wrote in message
...
Stormin Mormon wrote:

Well, a couple things come to mind.

Blade may be loose -- the engine relies on the "flywheel effect" of
the blade to keep the crankshaft turning.

Please double check that you added the correct ammount of oil.
Probably about 20 ounces.

As others have written, please check to see if something is tangled
in, or hitting the blade.

If the mower has a "safety handle", please check to see if the
safety
brake is fully releasing. Could explain the tight feel.

Might not be an issue. But, pull the spark plug out. Then yank the
rip
cord a couple times. Sometimes oil gets in the cylinder. With the
plug
out, the oil will spray out when you pull the starter cord. I've
seen
oil or gasoline in the cylinder, after a mower is tipped on its
side.



How long would you expect that oil to stay in the cylinder when he had
the engine RUNNING?

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10e12 furlongs per fortnight.

Thanks for the follow up.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Puddin' Man" wrote in message
...
On Sat, 16 Oct 2010 18:21:58 -0500, "HeyBub"
wrote:

I'll bet the problem is centered on the blade you removed/replaced.

Is is balanced? On upside down? Hitting something?

Mea Culpa!

I hadda lock washer on the blade bolt. Torqued the hull outa it.
Checked it when the problem first arose. Looked OK.

But it weren't. Blade rattled loose again. Sounded damned funny
for a loose blade, too.

Thanks,
P

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."