I have a hand-start lawnmower that stopped running recently. It is a Briggs
& Stratton, about 5 yrs old, and gets medium usage. It has given me no
problems until now.

The cylinder appears to be getting a fuel/oil mix delivered but is not
getting spark. I have pulled the plug, checked it for fouling and proper
gap, and grounded out the 'outer' terminal of the plug while connected to
the plug wire and not seen a spark when cranking the engine. Finally, I
wound up jamming the tip of my little finger in the plug boot and while my
thumb was grounded to the motor head cranked the engine. No pulses into my
hand so unless somebody tells me otherwise, I am confident my primary issue
is the 'spark'.

I removed the engine covers and see an electronic device similar to the
device in the following link:

http://science.howstuffworks.com/question375.htm

My flywheel looks almost identical to that though scaled up a bit in size.
Soooooo........ I have read about coils elsewhere at that above link and am
left with more questions (from more knowledge) than I started. I have
checked the 'safety' aspects of the mower to be sure they are not
intervening (the mechanism that breaks the circuit in case you release a
lever up at the top of the handle that is required to be depressed during
operation).

1) I read 4.5K ohm between the plug wire and the engine block.

2) I have very lightly sanded the track of the flywheel the travels under
the coil poles(?) to remove some light rust on the flywheel and be sure the
gap between the flywheel and coil was consistent.

Sooooo, unless you think otherwise, my guess is that the condenser/cap of
the magneto/coil is bad. (It seems like I might still feel a little jolt at
the plug wire - just not as much as normal - unless the cap is shorted out,
but then wouldn't I read a short to ground from the plug wire?)

Anyway, thanks for your time if you have read this.

--
For emails, don't forget to 'fix' the address.
A special place in hell awaits spammers!!!





http://groups-beta.google.com/group/...97f2ea555c8883

On Mon, 17 Jan 2005 04:42:04 GMT, "ProdigySBC_SUX"
wrote:

I have a hand-start lawnmower that stopped running recently. It is a Briggs
& Stratton, about 5 yrs old, and gets medium usage. It has given me no
problems until now.

The cylinder appears to be getting a fuel/oil mix delivered but is not
getting spark. I have pulled the plug, checked it for fouling and proper
gap, and grounded out the 'outer' terminal of the plug while connected to
the plug wire and not seen a spark when cranking the engine. Finally, I
wound up jamming the tip of my little finger in the plug boot and while my
thumb was grounded to the motor head cranked the engine. No pulses into my
hand so unless somebody tells me otherwise, I am confident my primary issue
is the 'spark'.

I removed the engine covers and see an electronic device similar to the
device in the following link:

http://science.howstuffworks.com/question375.htm

My flywheel looks almost identical to that though scaled up a bit in size.
Soooooo........ I have read about coils elsewhere at that above link and am
left with more questions (from more knowledge) than I started. I have
checked the 'safety' aspects of the mower to be sure they are not
intervening (the mechanism that breaks the circuit in case you release a
lever up at the top of the handle that is required to be depressed during
operation).

1) I read 4.5K ohm between the plug wire and the engine block.

2) I have very lightly sanded the track of the flywheel the travels under
the coil poles(?) to remove some light rust on the flywheel and be sure the
gap between the flywheel and coil was consistent.

Sooooo, unless you think otherwise, my guess is that the condenser/cap of
the magneto/coil is bad. (It seems like I might still feel a little jolt at
the plug wire - just not as much as normal - unless the cap is shorted out,
but then wouldn't I read a short to ground from the plug wire?)

Anyway, thanks for your time if you have read this.


The last time I worked on one I found that it had a set of points
inside a housing that was under the flywheel. That was quite a while
ago and they might be all electronic now. But the fix on mine was to
file and adjust the points, just like on an old car.
--
Elbridge Gerry, of Massachusetts:

"What, sir, is the use of militia? It is to prevent the
establishment of a standing army, the bane of liberty. . .
Whenever Government means to invade the rights and liberties of
the people, they always attempt to destroy the militia, in order
to raise a standing army upon its ruins." -- Debate, U.S. House
of Representatives, August 17, 1789

I've worked on a bunch of those. Point gap is .020 inches at the widest part
of the cycle. They worked well for a lot of years. I can't remember when
they went electronic, but it was at least five years ago.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"AZGuy" wrote in message
...

The last time I worked on one I found that it had a set of points
inside a housing that was under the flywheel. That was quite a while
ago and they might be all electronic now. But the fix on mine was to
file and adjust the points, just like on an old car.
--
Elbridge Gerry, of Massachusetts:

"What, sir, is the use of militia? It is to prevent the
establishment of a standing army, the bane of liberty. . .
Whenever Government means to invade the rights and liberties of
the people, they always attempt to destroy the militia, in order
to raise a standing army upon its ruins." -- Debate, U.S. House
of Representatives, August 17, 1789

The ignition module is a likely cause, test the coil first to rule it
out.

It is a Briggs
& Stratton, about 5 yrs old, and gets medium usage. It has given me no
problems until now.
CY: OK, so it's fairly recent.


The cylinder appears to be getting a fuel/oil mix delivered but is not
getting spark.
CY: So, it's two cycle?


CY: I may be mistaken, but I think now days the coil and ignition module
are
all part of the same assembly. So, if the ground wire isn't killing it,
and
the magnet is spinning past th e coil, you should get spark. If not, you
replace the coil and module assembly.

'Walking' lawnmower.

4-cycle? Not sure - I don't have to pre-mix oil and gas. (see more below.)

I replaced the coil/ignition assembly and now have spark back at the plug.
Unfortunately, it still won't start.

I have left the plug connected to the plug wire and grounded out the 'body'
of the plug and seen what appears to be consistent and good spark when
cranking the engine. There is fuel getting to the cylinder because I see it
on the plug when I pull it after cranking. I can't understand why I would
have two different failures at the same time. I am going to change my gas
out and see what happens. (I usually run the mower off of the same oil/gas
mix I run through the weedeater. One of the mechanics at a lawnmower shop
suggested it and said the mower engine would actually last longer for it.)

Q: Even though I see the plug sparking when I pull the start rope, can a
plug still be 'bad' and part of my problem? I think it is a Champion
RJ19LM. The manual sez that in some places (e.g., CA) the plugs will have a
resistor in them to reduce EMI emissions. If the place I am buying the plug
has any idea whether the plug has a resistor I will try to get the
non-resistor version.

My manual for my Ryobi line trimmer at least came with directions on how to
adjust the carburetor but this manual for the Murray mower / B&S engine
unfortunately doesn't have any such information. I'll start with a new plug
unless people here feel that mine is good.

Thanks.

You are running 2 stroke mix in a 4 stroke, that will carbon up the
motor. Your plug is wet and you have spark, so you are flooding it, Keep
choke off and spray in some either. Or even at 5 yrs your compression
may be to low to run it, test compression. Or a few other things.

"m Ransley" wrote in message
...
You are running 2 stroke mix in a 4 stroke, that will carbon up the
motor. Your plug is wet and you have spark, so you are flooding it, Keep
choke off and spray in some either. Or even at 5 yrs your compression
may be to low to run it, test compression. Or a few other things.

Ok - all good info. I'll go chew on this for a while. I have had concerns
the engine was getting flooded because the dang plug has been dripping
sometimes when I pulled it. But here's the clincher about your advice with
respect to this mower: In their effort to make it as idiot-proof as
possible, I have no control over the throttle or choke.

Typically, I pull the CPSC (CPS?) lever, tie it down with some cord, push
the priming bulb a couple of times, crank the engine 2-3 times, and go. I
have no control over speed ot anything. Once I put the wheels in gear I can
only disengage them by releasing the CPSC lever which also kills the engine.

It has to have a choke find its position-setting with respect to cable
setting and try starting without or minimum choke. Plug or more could be
bad you need a blue not yellow spark. Is air filter clogged. It is
possible running 2 stroke you carboned up the valves and they do not
seat anymore lowering compression to much to have power. But the right
mix of gas and air and it should fire. Try Either in the carb with choke
off.

Somewhere is a carb, choke, speed control. Look on the carburator.

yeah, air filter, that got me once, after working on an engine, I had
it upside down for a while, the oil had dripped onto the air filter
clogging it. I removed the air filter and it started right up.

Mark

(Might have the answer... but it's on the bottom)

It is a Briggs
& Stratton, about 5 yrs old, and gets medium usage. It has given me no
problems until now.
CY: OK, so it's fairly recent.


The cylinder appears to be getting a fuel/oil mix delivered but is not
getting spark.
CY: So, it's two cycle?


CY: I may be mistaken, but I think now days the coil and ignition module
are
all part of the same assembly. So, if the ground wire isn't killing it,
and
the magnet is spinning past th e coil, you should get spark. If not, you
replace the coil and module assembly.

'Walking' lawnmower.

4-cycle? Not sure - I don't have to pre-mix oil and gas. (see more below.)
CY: If it's got a dipstick and crankcase, that's a "4-cycle".


I replaced the coil/ignition assembly and now have spark back at the plug.
Unfortunately, it still won't start.

I have left the plug connected to the plug wire and grounded out the 'body'
of the plug and seen what appears to be consistent and good spark when
cranking the engine. There is fuel getting to the cylinder because I see it
on the plug when I pull it after cranking. I can't understand why I would
have two different failures at the same time.
CY: Might be just one....


I am going to change my gas
out and see what happens. (I usually run the mower off of the same oil/gas
mix I run through the weedeater. One of the mechanics at a lawnmower shop
suggested it and said the mower engine would actually last longer for it.)
CY: I can't comment on that, but it shouldn't hurt.


Q: Even though I see the plug sparking when I pull the start rope, can a
plug still be 'bad' and part of my problem?
CY: Yes, possible, but not very likely.

I think it is a Champion
RJ19LM. The manual sez that in some places (e.g., CA) the plugs will have a
resistor in them to reduce EMI emissions. If the place I am buying the plug
has any idea whether the plug has a resistor I will try to get the
non-resistor version.
CY: Champion did have some quality problems.


My manual for my Ryobi line trimmer at least came with directions on how to
adjust the carburetor but this manual for the Murray mower / B&S engine
unfortunately doesn't have any such information. I'll start with a new plug
unless people here feel that mine is good.
CY: Saving the best for last. If you hit a rock, the flywheel keeps going.
Shears a soft metal "key" and rotates out of tiem with the rest of the
motor. On the older mowers, that means no spark. Cause the magnet on the
flywheel is now out of time with the points. On the new electronic mowers,
you stillg et spark. But it's out of time with the cylinder. The way to
check is to pull the motor cover off the top. Take the big nut off the
center of the crank shaft (hold the blade with your boot under the deck
while you're cranking on the nut). Look down from the top. there should be a
notch in the crank shaft, and a notch in the flywheel. And they should be at
the same place. If the two notches aren't lined up, you need a new flywheel
key. Which is a whole new adventure.....


Thanks.
CY: Y'welcome.

Plugs by AC or NGC have worked well for me.

Leave plug out, and give the ripcord a couple yanks -- tht dries things out
within the cylinder.

--

Christopher A. Young
Learn more about Jesus
www.lds.org
www.mormons.com


"ProdigySBC_SUX" wrote in message
om...

"m Ransley" wrote in message
...
You are running 2 stroke mix in a 4 stroke, that will carbon up the
motor. Your plug is wet and you have spark, so you are flooding it, Keep
choke off and spray in some either. Or even at 5 yrs your compression
may be to low to run it, test compression. Or a few other things.

Ok - all good info. I'll go chew on this for a while. I have had concerns
the engine was getting flooded because the dang plug has been dripping
sometimes when I pulled it. But here's the clincher about your advice with
respect to this mower: In their effort to make it as idiot-proof as
possible, I have no control over the throttle or choke.

Typically, I pull the CPSC (CPS?) lever, tie it down with some cord, push
the priming bulb a couple of times, crank the engine 2-3 times, and go. I
have no control over speed ot anything. Once I put the wheels in gear I can
only disengage them by releasing the CPSC lever which also kills the engine.

See new thread.... Part II. Thanks for all your help.