Briggs/Stratton 3.5 hp

'allo,

Over 1 year ago, somebody gave me an old MTD 20" mower with a
B&S 3.5 hp. Ran rough, so I cleaned the carb, changed oil, plug, etc.
Ran fine, better'n my newer Quantum 4hp. I garaged it as a backup
mower.

About a year later, after no further use, it won't start. Carb looks
fine. Evidently no spark. Tough to properly test: only one of me,
not enough hands. Pulled the plug, wired the safety bar, pulled
engine cover. Trying to test just turning the flywheel by hand. Even
put a multimeter (@ 500v ac) on it: just barely, barely moved.

I'd just pitch the unit if I had conclusive evidence that the
magneto (or whatever) was defective. But I've had 3.5's before and
never had a problem with spark (except plug replacement).

Anybody gotta inkling why such 3.5 would run fine 1 year ago,
fail to gen spark now?

Thx,
Puddin'

Pease pudding hot,
Pease pudding cold,
Pease pudding in the pot
Nine days old.

Puddin,

That the carb looks fine isn't definitive. Get some starting fluid, spray
it into the carb throat, and see if it will start. When you store an engine
for a long time either run it dry or use a gas stabilizer.

Dave M.

"David Martel" wrote in message
link.net...
Puddin,

That the carb looks fine isn't definitive. Get some starting fluid,
spray
it into the carb throat, and see if it will start. When you store an
engine
for a long time either run it dry or use a gas stabilizer.


To test the spark, pull the plug, push it back into the plug wire, and prop
or wire the base of the plug to the engine metal. Then try to start it. The
spark
should be evident. If it is, you probably have a carb problem.

Bob

Wait till dark night time. Screw the plug out. snap the plug back into
the end of the plug wire. Pull safety handle down, and then yank the
rip cord. With no plug, there is no compression, so the motor spins
fine. Look at the gap of the plug to see if you see spark. Easier to
see in the dark night time.

The other guy is right, try a squirt of ether on the air filter (not
into the spark hole). See if it runs on ether.

Turning by hand probably not fast enough to fire the magneto.

--

Christopher A. Young
You can't shout down a troll.
You have to starve them.
..

"Puddin' Man" wrote in message
...
Briggs/Stratton 3.5 hp

'allo,

Over 1 year ago, somebody gave me an old MTD 20" mower with a
B&S 3.5 hp. Ran rough, so I cleaned the carb, changed oil, plug, etc.
Ran fine, better'n my newer Quantum 4hp. I garaged it as a backup
mower.

About a year later, after no further use, it won't start. Carb looks
fine. Evidently no spark. Tough to properly test: only one of me,
not enough hands. Pulled the plug, wired the safety bar, pulled
engine cover. Trying to test just turning the flywheel by hand. Even
put a multimeter (@ 500v ac) on it: just barely, barely moved.

I'd just pitch the unit if I had conclusive evidence that the
magneto (or whatever) was defective. But I've had 3.5's before and
never had a problem with spark (except plug replacement).

Anybody gotta inkling why such 3.5 would run fine 1 year ago,
fail to gen spark now?

Thx,
Puddin'

Pease pudding hot,
Pease pudding cold,
Pease pudding in the pot
Nine days old.

Bob F wrote:
"David Martel" wrote in message
link.net...
Puddin,

That the carb looks fine isn't definitive. Get some starting fluid,
spray
it into the carb throat, and see if it will start. When you store an
engine
for a long time either run it dry or use a gas stabilizer.


To test the spark, pull the plug, push it back into the plug wire, and prop
or wire the base of the plug to the engine metal. Then try to start it. The
spark
should be evident. If it is, you probably have a carb problem.

Bob
..
My 3.5 B and S mower is acting the same. It was running rough and
surging, so had changed the plug; put in a new carburetor kit and
checked the magneto clearance under the flywheel and it ran fine for a
couple of weeks of occasional use.
Then it stopped. Haven't bothered since cos end of season.
Howver someone reminded me to check the the safety off switch; when I
let go of the safety bar (a sort of deadman's lever on the handle which
must be held down to start and run) a switch operated by a cable from
the lever kills the ignition circuit.
So just a suggestion if the OP has a mower with a 'safety stop' lever

"Stormin Mormon" wrote in message
...
Wait till dark night time. Screw the plug out. snap the plug back into
the end of the plug wire. Pull safety handle down, and then yank the
rip cord. With no plug, there is no compression, so the motor spins
fine. Look at the gap of the plug to see if you see spark. Easier to
see in the dark night time.

The other guy is right, try a squirt of ether on the air filter (not
into the spark hole). See if it runs on ether.

A squirt of gas into the air intake works fine also.

Bob

On Sat, 21 Oct 2006 00:33:35 GMT, "Stormin Mormon"
wrote:

Wait till dark night time. Screw the plug out. snap the plug back into
the end of the plug wire. Pull safety handle down, and then yank the
rip cord.

Pardone, mssr, but that requires (at least) 3 (very long)
arms/hands. I have only 2. :-)

With no plug, there is no compression, so the motor spins
fine. Look at the gap of the plug to see if you see spark. Easier to
see in the dark night time.

'Tis a test that I've run many times. If spark gen is functional,
I've had no trouble seeing it in the daytime.

The other guy is right, try a squirt of ether on the air filter (not
into the spark hole). See if it runs on ether.

May be some out the garage ...

Turning by hand probably not fast enough to fire the magneto.

You may be right bout thatun.

Thanks,
P

Pease pudding hot,
Pease pudding cold,
Pease pudding in the pot
Nine days old.

On Sat, 21 Oct 2006 08:00:57 -0700, "Bob F"
wrote:


"Stormin Mormon" wrote in message
. ..
Wait till dark night time. Screw the plug out. snap the plug back into
the end of the plug wire. Pull safety handle down, and then yank the
rip cord. With no plug, there is no compression, so the motor spins
fine. Look at the gap of the plug to see if you see spark. Easier to
see in the dark night time.

The other guy is right, try a squirt of ether on the air filter (not
into the spark hole). See if it runs on ether.

A squirt of gas into the air intake works fine also.

All I ever needed. I had pulled the air filter. Watched
while working the bulb which squirted gas into the carb
throat. Damned well know it was getting gas.

Thx,
P

Pease pudding hot,
Pease pudding cold,
Pease pudding in the pot
Nine days old.

On Sat, 21 Oct 2006 17:34:22 GMT, Puddin' Man
wrote:

On Sat, 21 Oct 2006 00:33:35 GMT, "Stormin Mormon"
wrote:

Wait till dark night time. Screw the plug out. snap the plug back into
the end of the plug wire. Pull safety handle down, and then yank the
rip cord.

Pardone, mssr, but that requires (at least) 3 (very long)
arms/hands. I have only 2. :-)

With no plug, there is no compression, so the motor spins
fine. Look at the gap of the plug to see if you see spark. Easier to
see in the dark night time.

'Tis a test that I've run many times. If spark gen is functional,
I've had no trouble seeing it in the daytime.

The other guy is right, try a squirt of ether on the air filter (not
into the spark hole). See if it runs on ether.

May be some out the garage ...

Y'all were both right.

It's wierd. I work the primer bulb, can see gas
shooting into the throat of the carb. But it
won't start.

Shoot some ether in it and it fires. Then
dies.

Guess I gotta dissemble the catb again ...

Muchas Gracias,
Puddin'

Pease pudding hot,
Pease pudding cold,
Pease pudding in the pot
Nine days old.

Ah, but the events happen at different times.

--

Christopher A. Young
You can't shout down a troll.
You have to starve them.
..

"Puddin' Man" wrote in message
...
On Sat, 21 Oct 2006 00:33:35 GMT, "Stormin Mormon"
wrote:

Wait till dark night time. Screw the plug out. snap the plug back
into
the end of the plug wire. Pull safety handle down, and then yank the
rip cord.

Pardone, mssr, but that requires (at least) 3 (very long)
arms/hands. I have only 2. :-)