No Spark to Tecumseh Tiller Engine!

Golodkin

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Apr 18, 2014
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Got it off...easy once the tank's removed.

Bad coil, new one arrives Tuesday.

Thanks, everyone!
 

Golodkin

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OK, here's the latest:

Got the new coil, installed it with ~.025" clearance at the magnet, put it back together -- still no spark!

Nothing, not even to ground!

How can this even be?

I read of this same misfortune with someone else's engine, but didn't see how it resolved...if it did.

Are those wrong clearances for this model?

Did I lose my mind and install it backwards? [Spark plug cable faces outward toward the pull starter]

Is it possible to test the coil?
 

jp1961

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Try taking a 3" x 5" card which is roughly .008" thick, doubling it .016" and reset the coil closer to the flywheel.

I have heard of flywheel magnet loosing their magnetism, does it pull a screwdriver close to it?

Other than it having points and condensor, it's possible the new coil is bad too.

Even though the spark plug is relatively new, try another one.

Regards

Jeff
 

Golodkin

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Try taking a 3" x 5" card which is roughly .008" thick, doubling it .016" and reset the coil closer to the flywheel.

I have heard of flywheel magnet loosing their magnetism, does it pull a screwdriver close to it?

Magnet certainly seems strong enough.

I've got a piece of card here that's .017" by micrometer. I may try something thinner. The tolerances were supposedly from .012" to .035"

Other than it having points and condensor

No, none of those. This is supposed to be simple. :laughing:

it's possible the new coil is bad too.

That sounds like my luck!

Even though the spark plug is relatively new, try another one.

If I can, I'm simply going to eliminate it from the equation by using an ignition spark tester to ground. Of course, I have at least two of these but am having a time finding either of them.

Thanks!
 

jp1961

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You've already checked the grounding wire, they sometimes abrade away their plastic coating causing a short to ground. These are the only things I can think of.

I know the feeling of having 6 of one tool and not being able to find any.

Take a breather,,,,find your Zen, you'll get this ( I find either hot tea helps or lots of alcohol,,,LOL).

Jeff
 

Golodkin

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Man, what a nightmare!

Latest: I ordered a different coil from a different seller. Got it today and put it in, gapped it, buttoned it up and NO SPARK AGAIN!

This is SUPPOSED to be the correct coil, superseding the old one. Fits perfectly...but it doesn't look the same and I wonder what's up. The odds against two different coils from two different manufacturers being dead out of the box seems astronomical.

Here are the three culprits:

https://i.imgur.com/YFsZABs.jpg

Here's the old coil:

https://i.imgur.com/QgAZtol.jpg

Thoughts?
 

tadawson

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Clearly it isn't the coil . . .

Have you ever put an ohmmeter to the kill lead as I suggested before you started throwing parts at it to verify that it is switching properly? This still screams that to me . . .
 

Golodkin

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Have you ever put an ohmmeter to the kill lead as I suggested before you started throwing parts at it to verify that it is switching properly? This still screams that to me . . .

I did better than that. I totally removed the kill lead from the circuit. Completely. It can't be a factor.

I'm becoming convinced that in fact the original is substantially different from these later replacements. Look at the picture. It has a larger coil, bigger frame, larger resin body. It's a drop-in fit...but these replacements simply don't work. Never mind Chinese manufacture.

I'm getting about done with this experiment. I'm going to put a closer gap on tomorrow, and if that doesn't work, I'm off to the local mower shop to drop $43 + tax for their idea of a proper coil. It may turn out that these updated coils are erroneous.
 

Golodkin

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[Later:] It lives! Big blue spark.

How I got to this point is a very interesting and edifying tale, which I'll get to tomorrow.

I also think I found the fault in the original coil.

Photos follow.
 

Golodkin

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Observe!

OK, the replacement coil was good from the start, though my frame of mind wasn't. I was tired and discouraged, and I pulled the starter cord only twice in bright sunlight. The arc was out of my field of vision, and I was still wearing hearing protectors -- so I never saw nor heard anything relevant. Disgusted and assuming more bad luck, I just went in the house.

HOWEVER...I went back out at around ten PM (minus my hearing protectors) and gave it a pull and I saw a huge blue spark.

So, victory on the first real try. It starts on the first pull, goes fine.

So what was wrong with the first coil?

Here, look at this:

CoilView.JPG

Note that the coil wire or some other component is soldered to the metal strap.

But look at it from another angle:

CoilBreak.JPG

The metal strap was never properly prepped nor fluxed and the wire simply separated by about .003" leaving a stone dead coil.

Yes, I am going to demand a refund!
 
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