I have a 14.5 hp Tecumseh engine on my riding lawn mower -- but no
spark at the plug. After tremendous amounts of troubleshooting I blame
the ignition module. Note: I've disconnected the grounding cutoff
wire, and there are no other wires on the module excpet for the spark
plug wire. My problem: with a spark tester connected to the spark plug
there is only a dim flash of light. However, when I connect the spark
tester directly to motor ground, there is a bright flash! I've changed
the plugs out several times. This sounds to me like the module is
producing a diminished output which is strong enough to light the spark
tester but not enough to fire across the spark plug. BUT....... I had
thought these modules were either totally GOOD or totally BAD, period.
Please, any comments? Am I overlooking something? Note: the magnets
on the flywheel seem quite strong. The air gap is perfect. HELP!!
Thanks.

EW

According to :
I have a 14.5 hp Tecumseh engine on my riding lawn mower -- but no
spark at the plug. After tremendous amounts of troubleshooting I blame
the ignition module. Note: I've disconnected the grounding cutoff
wire, and there are no other wires on the module excpet for the spark
plug wire. My problem: with a spark tester connected to the spark plug
there is only a dim flash of light. However, when I connect the spark
tester directly to motor ground, there is a bright flash! I've changed
the plugs out several times. This sounds to me like the module is
producing a diminished output which is strong enough to light the spark
tester but not enough to fire across the spark plug. BUT....... I had
thought these modules were either totally GOOD or totally BAD, period.
Please, any comments? Am I overlooking something? Note: the magnets
on the flywheel seem quite strong. The air gap is perfect. HELP!!

Sounds like a poor connection on the module. Ie: bad ground.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

Thanks Chris, but there are no ground connections on an ignition module
like this. The only connection is the spark plug wire. The module is
mounted on the engine frame (good solid mount). There is an engine
cutoff wire that goes to the starter switch, but it is presently
disconnected for troubleshooting purposes, according to the manual.
Bottom line: I do get an output but not a strong one. Perhaps a
shorted coil winding inside the potted module that allows only a
portion of the inductance to be used...?

EW

On 1 Nov 2005 14:10:23 -0800, wrote:

I have a 14.5 hp Tecumseh engine on my riding lawn mower -- but no
spark at the plug. After tremendous amounts of troubleshooting I blame
the ignition module. Note: I've disconnected the grounding cutoff
wire, and there are no other wires on the module excpet for the spark
plug wire. My problem: with a spark tester connected to the spark plug
there is only a dim flash of light. However, when I connect the spark
tester directly to motor ground, there is a bright flash! I've changed
the plugs out several times. This sounds to me like the module is
producing a diminished output which is strong enough to light the spark
tester but not enough to fire across the spark plug. BUT....... I had
thought these modules were either totally GOOD or totally BAD, period.
Please, any comments? Am I overlooking something? Note: the magnets
on the flywheel seem quite strong. The air gap is perfect. HELP!!
Thanks.

EW

A very helpful Tecumseh rep hangs out on the yahoo group Tecumseh
Engines. You have to join but you will get the best advice.

You have pretty well answered your own question. There are no other
components to that system other than the magnets, module, leads, plugs and
kill switch(es). They can produce a weak spark, sometimes one strong enough
to jump the plug gap but not strong enough to jump the gap under compression
and ignite the fuel mixture. A strong spark can be created, but at the wrong
time, if the flywheel key is sheared. I think your module is bad. [I have
been wrong a few times. :)]
Don Young

wrote in message
oups.com...
Thanks Chris, but there are no ground connections on an ignition module
like this. The only connection is the spark plug wire. The module is
mounted on the engine frame (good solid mount). There is an engine
cutoff wire that goes to the starter switch, but it is presently
disconnected for troubleshooting purposes, according to the manual.
Bottom line: I do get an output but not a strong one. Perhaps a
shorted coil winding inside the potted module that allows only a
portion of the inductance to be used...?

EW

On 1 Nov 2005 14:10:23 -0800, wrote:

I have a 14.5 hp Tecumseh engine on my riding lawn mower -- but no
spark at the plug. After tremendous amounts of troubleshooting I blame
the ignition module. Note: I've disconnected the grounding cutoff
wire, and there are no other wires on the module excpet for the spark
plug wire. My problem: with a spark tester connected to the spark plug
there is only a dim flash of light. However, when I connect the spark
tester directly to motor ground, there is a bright flash! I've changed
the plugs out several times. This sounds to me like the module is
producing a diminished output which is strong enough to light the spark
tester but not enough to fire across the spark plug. BUT....... I had
thought these modules were either totally GOOD or totally BAD, period.
Please, any comments? Am I overlooking something? Note: the magnets
on the flywheel seem quite strong. The air gap is perfect. HELP!!
Thanks.

Have you tried using a spark plug as a tester? Unscrew it from the
negine, connect it back to the wire, and have someone hold the metal
threaded part against the block, or use a wire with aligator clips on
each end.

IIUC, it's harder for the spark to jump the gap when the gas in the
cylinder is compressed, but not that much harder.

I don't trust your tester. How much did it cost, and what is the
essence of it,. I have an incredibly cheap one, with a flashlight
bulb or neon light in it, I forget. I think a test with the spark
plug is a better test.

I have 7 broken mowers this year, and two seem to need magneto coils.
But I'm not sure. When I had no mower, I would have eagerly spent the
money, but 2 or the 5 now work. Still, I can't throw the others away,
even though the original owners did. (They look new)

(I've given two to a repairman nearby.)

EW


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"mm" wrote in message
...
On 1 Nov 2005 14:10:23 -0800, wrote:

I have a 14.5 hp Tecumseh engine on my riding lawn mower -- but no
spark at the plug. After tremendous amounts of troubleshooting I blame
the ignition module. Note: I've disconnected the grounding cutoff
wire, and there are no other wires on the module excpet for the spark
plug wire. My problem: with a spark tester connected to the spark plug
there is only a dim flash of light. However, when I connect the spark
tester directly to motor ground, there is a bright flash! I've changed
the plugs out several times. This sounds to me like the module is
producing a diminished output which is strong enough to light the spark
tester but not enough to fire across the spark plug. BUT....... I had
thought these modules were either totally GOOD or totally BAD, period.
Please, any comments? Am I overlooking something? Note: the magnets
on the flywheel seem quite strong. The air gap is perfect. HELP!!
Thanks.

Have you tried using a spark plug as a tester? Unscrew it from the
negine, connect it back to the wire, and have someone hold the metal
threaded part against the block, or use a wire with aligator clips on
each end.

IIUC, it's harder for the spark to jump the gap when the gas in the
cylinder is compressed, but not that much harder.

I don't trust your tester. How much did it cost, and what is the
essence of it,. I have an incredibly cheap one, with a flashlight
bulb or neon light in it, I forget. I think a test with the spark
plug is a better test.

I have 7 broken mowers this year, and two seem to need magneto coils.
But I'm not sure. When I had no mower, I would have eagerly spent the
money, but 2 or the 5 now work. Still, I can't throw the others away,
even though the original owners did. (They look new)

(I've given two to a repairman nearby.)


mm...........

Yes, I have used several spark plugs to test the module -- and thanks for
mentioning it. There is no bright spark at all when grounding the bottom of
the plug (sometimes I get a faint flash). The spark plug tester cost me
over $18, but as you say it is not as good as the plug method. After all
the helpful responses I'm convinced it's the ignition module. In fact, I've
paid for and ordered it, and I can't get my money back if it's NOT the
problem. But it can be nothing else!

Thank you all!!

EW

Note: I've removed my original messages from the Gmail newsgroup, since
Gmail insisted on using my email address as my "nickname." Grrrrrrrr......
Here comes the SPAM!

"Andy Asberry" wrote in message
...

A very helpful Tecumseh rep hangs out on the yahoo group Tecumseh
Engines. You have to join but you will get the best advice.

I'm on my way!! Thanks.

EW

make sure there is no spilled gas around when you do those tests

Mark

According to mm :
Have you tried using a spark plug as a tester? Unscrew it from the
negine, connect it back to the wire, and have someone hold the metal
threaded part against the block, or use a wire with aligator clips on
each end.

This is a reasonably reliable (and easy) test. However, it still may
not be enough spark.

The proper way is to see if the spark will jump a full 1/4". Our
small engines instructor has a tester made in the following way:

Take a spark plug and saw off the threaded portion, leaving central
insulator and spark gap center pin intact. He then fastened a small bracket
with a screw in it, so he could adjust the gap between the screw and the
spark gap center pin. A grounding strap with alligator clip is then
fastened to the body. Attach the clip to the motor frame, the spark
wire to the top of the modified plug, and see if you can pull a spark
across the 1/4".
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

I am a curb trash scavenger also. Gasoline engines must have gas,
spark and compression to run. Most engine problems I've pinned down
have been no spark or low compression. This excludes the normal dirty
carb and dirt in gas tank.
Squirt a little gas right into the carb. (not in a closed area)
If that doesn't help. Check for spark.
If spark, check compression. Compression has to be above 70 psi. Lot
of times it will run with low compression and 1/2 to 3/4 choke but not
well.

On Thu, 03 Nov 2005 03:44:42 -0000, (Chris
Lewis) wrote:

According to mm :
Have you tried using a spark plug as a tester? Unscrew it from the
negine, connect it back to the wire, and have someone hold the metal
threaded part against the block, or use a wire with aligator clips on
each end.

This is a reasonably reliable (and easy) test. However, it still may
not be enough spark.

The proper way is to see if the spark will jump a full 1/4". Our

I was never sure a lawnmower should have such a good spark (compared
to a car). I'm happy to hear that it does.

Is this also true with the points and capacitor ignition on a lawn
mower (and not just the electronic ignition)?

small engines instructor has a tester made in the following way:

Take a spark plug and saw off the threaded portion, leaving central
insulator and spark gap center pin intact. He then fastened a small bracket
with a screw in it, so he could adjust the gap between the screw and the
spark gap center pin. A grounding strap with alligator clip is then
fastened to the body. Attach the clip to the motor frame, the spark
wire to the top of the modified plug, and see if you can pull a spark
across the 1/4".


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me know if you have posted also.

On 2 Nov 2005 19:42:46 -0800, "Mark" wrote:

make sure there is no spilled gas around when you do those tests

Mark

I never caused a problem with a lawnmower, but I once was testing the
spark of a V-8 by holding a plug against the block, while to save
time, I was also spraying ether. Don't do that.

The thing blew up with a big bang, blowing the valve cover lip up at 3
or 4 places between bolts.

Fortunately, I'd learned not to move, or I would have banged my head
good on the metal edge of the hood.

I was fine, but I had to replace the valve cover. Since I knew of no
junkyards in NYC, I had to go to a speed shop, and my brother had one
chrome and one regular valve cover until he finally sold the car. (I
hope he remembered to give the buyer the other chrome cover.)

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On Wed, 2 Nov 2005 15:59:06 -0600, "LoneStar"
wrote:


Have you tried using a spark plug as a tester? Unscrew it from the
negine, connect it back to the wire, and have someone hold the metal
threaded part against the block, or use a wire with aligator clips on
each end.

IIUC, it's harder for the spark to jump the gap when the gas in the
cylinder is compressed, but not that much harder.

I don't trust your tester. How much did it cost, and what is the
essence of it,. I have an incredibly cheap one, with a flashlight
bulb or neon light in it, I forget. I think a test with the spark
plug is a better test.

I have 7 broken mowers this year, and two seem to need magneto coils.
But I'm not sure. When I had no mower, I would have eagerly spent the
money, but 2 or the 5 now work. Still, I can't throw the others away,
even though the original owners did. (They look new)

(I've given two to a repairman nearby.)


mm...........

Yes, I have used several spark plugs to test the module -- and thanks for
mentioning it. There is no bright spark at all when grounding the bottom of
the plug (sometimes I get a faint flash). The spark plug tester cost me
over $18, but as you say it is not as good as the plug method. After all

That must be a lot better than mine, which cost iirc one dollar!

One of my chores for today is to connect it to a known working mower
and see if it lights up. If that doesn't work, I'll try it again
after dark and see if it lights up then.

the helpful responses I'm convinced it's the ignition module. In fact, I've
paid for and ordered it, and I can't get my money back if it's NOT the
problem. But it can be nothing else!

That's the way I feel about those two mowers, but I've run out of time
this summer. Another chore today is to make shelves for the mowers
and stack them up in two piles of two and one pile of one. I'm not
making a shelf so much as putting a 4x2 foot sheet of t1-11 on top of
one, and then balancing the other on top of that. I had one last
winter covered with plastic and a board, and it was clean as new when
spring came.

Thank you all!!
EW
Note: I've removed my original messages from the Gmail newsgroup, since
Gmail insisted on using my email address as my "nickname." Grrrrrrrr......
Here comes the SPAM!

Donm't know much about gmail. or biology or geometry.

Remove NOPSAM to email me. Please let
me know if you have posted also.