Small engine (Tecumseh)help please

[Acorn]

My Dad has an older Sears rider with I believe a 10 horse Tecumseh vertical shaft engine. It started acting up on him last week and died. I went to try and get it started. Long story made short. No spark. I cleaned the flywheel magnets and coil but still nothing. There is a small spade terminal on the coil with a wire to ground. If I pull the wire off it runs. Connect the wire no spark, no run.
Why when I disconnect it the engine runs? Is it an internal short to the ground wire in the coil that's giving me no spark?
I thought the little spade terminal was to short the coil to ground to kill the engine but it's only a foot long and I followed it from end to end and there is no switch to turn the ignition on or off.
Hope this makes sense.

Thanks

 

[snowman2]

You may have a wire from the ignition switch shorting to ground on a piece of chassis I would trace were that wires from the switch to see if there are any frayed bits
Lots of luck Harv

 

[Cholo]

If you don't find the answer, Forum member *graygun* has lots of experience with small engines. You could shoot him a PM if he doesn't see this thread.

 

[GRAMPS 51]

Hi that wire is there to ground out the coil (to shut it off ) if you follow the throttle cable down to where it mounts to the engine look at it close and you will see how when you push the throttle down past idle it will ground out the other end of that wire chances are that wire is out of place or broken off and is grounded out possibly just out of adjustment

Gramps

 

[graygun]

Hi that wire is there to ground out the coil (to shut it off ) if you follow the throttle cable down to where it mounts to the engine look at it close and you will see how when you push the throttle down past idle it will ground out the other end of that wire chances are that wire is out of place or broken off and is grounded out possibly just out of adjustment

Gramps

Sounds right because it runs with the cable disconnected.

 

[Acorn]

The wire runs from the coil directly to the ground. I had it off completely. There is no switch just a 12" wire with spade terminals on both ends. The way its been wired since new, it never would have run, since the coil as wired is constantly grounded.

 

[graygun]

One end should be connected to a kill device like a spring-loaded cable or lever which forces the coil to ground,killing the ignition. Seems it got mis-connected somehow.

 

[Galaxiedan]

Seat switch? Some riders have a pressure switch that kills mower if you get off the seat

 

[Dave P.]

Acorn,
You're not seeing something correctly at the block/chassis end.
That wire is what grounds out the ignition to shut it off, if grounded
it will have no spark ( which you already know ).
Usually the block end goes to a terminal that is isolated by a bit
of plastic or bakelite with either a grounding contact that the
throttle control hits at idle/stop position to shut down the spark
or another wire that connects to the chassis wiring ( key switch, safety circuit etc ).
Unless somebody has played with it before you got there and connected the wire
wrong.....
Dave

 

[coach]

Sounds like it could be a malfunctioning safety switch like a seat switch, neutral start switch, etc.

 

[Acorn]

Seat switch is disconnected. I know what you all are saying about the wire being for a shut off. That's what I thought too. Dad didn't have the engine shroud or tank off which you pretty much have to do to get to the coil and wire. My future BIL was cutting the grass with it when it started sputtering and died. Dad just threw a tarp over it where it died.

 

[HerrMesser]

Acorn
I am going to recommend checking with some of the guys on the Garden Tractor talk forum. there are a lot very knowledgeable people on there.

http://gardentractortalk.com/

Rad

 

[graygun]

Also,YouTube may have relevant videos.