Old Troy Bilt Horse Tiller - Question

[Dennis Peacock]

I have an old Troy Bilt Horse tiller.
It has a Tecumseh 8 HP engine on it. I just rebuilt the carb on it....funny that it doesn't have any "fire". Points are new but I don't think the condenser is new. I'm troubleshooting why it doesn't have any spark. Anybody here got any experience with small engines like this of this vintage?

[Lee Schierer]

Not much to them. The points and condenser are under the fly wheel. The point setting is pretty critical. I don't have my book, but I think it is .020. You also need to insure the fly wheel key is not partially sheared as timing is critical. I think the coil and spark plug wire are molded as one piece so the coil could be bad, but try squeezing the clip that fits over the spark plug so it fits tight. The plug could also be bad. I think the plug gap is .015 or .018 but you might find. I have a book at home that I can get the exact settings. PM me in a week and I can look it up.

[Bill Huber]

I think Lee has things going good on this, the only thing I will add is at one time a friend had a snow blower that had no spark, he brought to to me to fix.

After working on it for awhile I found that the kill switch wiring was shorting out on the metal flywheel cover.

[Duane Meadows]

There is a Magneto(coil) under the flywheel, and a magnet in(part of) the flywheel. Clean the magnet and magneto poles(fine sandpaper). That and the points and condenser(old word for capacitor) are about all there is to it. The flywheel key may keep it from running if extremely worn, bit will not prevent having spark. May not spark at the proper time, but it will still spark! Bill is also correct, a shorted to ground kill switch could be the issue as well. In extreme cases, it may be necessary to change the flywheel and magneto.

I would start with a new plug, points, and condenser.

[Dennis Peacock]

The points and condenser are mounted under a cover on the throttle side of the motor, opposite side of the gas tank. Coil and magnet are under the flywheel. The are now clean and put in new plug. Still no fire.

[Pat Barry]

Hey Dennis - is it possible the plug wire is bad?

[Keith Outten]

Dennis,

Disconnect the kill switch wire completely as Bill suggested. Most of the time when there is zero spark its a short in the kill switch or the wire itself.
.

[Duane Meadows]

If disconnecting the kill switch doesn't help, Either got a bad condenser, bad coil, or possible flywheel(rust has been known to ruin the magnet!). Also check to be sure the point gap is correct(the points actually close an open when the crankshaft rotates?).

Nothing else there!

[Dennis Peacock]

Points gap set to about .020 and they do move as the crank moves. Magnet appears to be good and lightly sanded the magnet and coil contact areas just to make sure. It has to be in the wiring or condenser. Narrowing it down now that I'm back at home.

[Lee Schierer]

Points gap set to about .020 and they do move as the crank moves. Magnet appears to be good and lightly sanded the magnet and coil contact areas just to make sure. It has to be in the wiring or condenser. Narrowing it down now that I'm back at home.

Dennis, I was wrong, by book was for a 6 Hp Tecumseh so I don't have the specs for an 8Hp. I would bet on a bad condenser, since a bad condenser would produce no spark at all. But it could also be the spacing between the magnets and the coils. As I recall, the clearance should be about .005". It is easy to set with two thicknesses of ordinary copy paper between the magnets and the coil armatures, assuming the coil is out side the flywheel. If it is inside, they make a special setup gauge that most small motor shops would have.

[Dennis Peacock]

Dennis, I was wrong, by book was for a 6 Hp Tecumseh so I don't have the specs for an 8Hp. I would bet on a bad condenser, since a bad condenser would produce no spark at all. But it could also be the spacing between the magnets and the coils. As I recall, the clearance should be about .005". It is easy to set with two thicknesses of ordinary copy paper between the magnets and the coil armatures, assuming the coil is out side the flywheel. If it is inside, they make a special setup gauge that most small motor shops would have.

Lee, the coil is under the flywheel. I'm familiar with setting the "air gap" on B&S engines back in the day, a simple index card was the perfect thickness to set the gap perfectly between the flywheel and the coil. My shop teacher taught us to check for proper fire by pinching the spark plug end of the wire between the thumb and index finger...then place the middle finger of the same hand against one of the head bolts. Take the other hand and spin the flywheel by hand and if the electrical charge reached all the way to your shoulder....the settings were good and all was good to go.
I haven't done small engine repair of this order in decades.!!! Brings back some good and some frustrating times.