Jump to content

Garden Tractors and Parts on eBay



Photo
- - - - -

Egad now there's no spark


  • Please log in to reply
3 replies to this topic

#1 KA1J OFFLINE  

KA1J
  • Member
  • Member No: 84822
  • 12 Thanks
  • 32 posts
  • Location: S.E. CT

Posted October 19, 2016 - 06:40 PM

There is now no spark on the 1984 ST110. 

 

The only history I have to offer is: The engine was running beautifully, I'd removed the shrouding to paint the parts two days ago. With the dipstick holder off I plugged the oil "hole" oil and started the engine to fine tune the carb. The plug blew out and splattered the oil inside the compartment. I cleaned it up, put the filler tube back, taped it in place with a wad of paper to keep it from hitting the starter gear ring. Started it and it started instantly, ran perfectly at high and low speeds. I removed the battery and started prepping the shrouding, then I removed the brake pads, insured all was right and put it back together.

 

Today I put the shrouding back on, Put it in neutral, connected the battery and tried starting it but the engine only turned over and it turns out there is no spark. I checked all the electrical connections thinking maybe oil had become a problem in a plug but after removing the ignition switch & seeing there was no oil on it and spraying all the connections with deoxit, there still is no spark.

 

There is a wire running to the coil which is kept from ground by a phenolic looking spacer, there is a bluish wire coming from the ignition switch which connects to that wire, with a spade lug. There is no 12V voltage to this wire but perhaps that is normal, the junction does short to ground. With the volt-ohm meter I found the body of the coil is shorted with this wire. 

 

There are two wires coming into a plug by the starter. on the mating side of the plug are two power diodes in reverse parallel with the common tip connected to a single wire plug. This plug runs under the starter & into the engine. Both of the diodes appear to be working in that each when tested separately, in place, show a forward voltage and none with the probes reversed. 

 

I'm stymied, I can't figure out what could have happened that there is no spark whatsoever in that I didn't do anything electrical at all while I dealt with the brakes & while paint was drying on the parts on the paper in the garage. Spent 4 hours today trying to get a spark but nothing.

 

I know there is a safety switch below the seat, maybe another somewhere that is open? There is the 30 amp fuse, are there any others that may be open?

 

How do I hot-wire it to exclude component failure like the coil or internal wiring?

 

Any ideas?

 

Thanks,

 

Gary


Edited by KA1J, October 19, 2016 - 06:47 PM.


#2 LilysDad ONLINE  

LilysDad

    Millennium Falcon

  • Senior Member
  • Contributor
  • Member No: 10443
  • 12,248 Thanks
  • 9,191 posts
  • Location: N. Illinois, DeKalb County

Posted October 19, 2016 - 07:16 PM

Do you really use 'egad' in every day english?!!



#3 KA1J OFFLINE  

KA1J
  • Member
  • Member No: 84822
  • 12 Thanks
  • 32 posts
  • Location: S.E. CT

Posted October 19, 2016 - 07:22 PM

I do. I try not to wear it out.



#4 KA1J OFFLINE  

KA1J
  • Member
  • Member No: 84822
  • 12 Thanks
  • 32 posts
  • Location: S.E. CT

Posted October 20, 2016 - 10:49 AM

Thanks to an off list suggestion and watching some youtube videos, I removed the kill wire to the magneto (never worked with a magneto before and had no clue how it works) and now the engine runs, so the problem is related to wiring or a bad switch. The seat switch is obvious to find but I've been unable to find where the brake switch is located on the ST110, the wiring harness makes it difficult to track the wiring. Anyone know where this is located on this ST110 so I can be sure it's working properly? 

 

Thanks.

 

Gary


Edited by KA1J, October 20, 2016 - 10:51 AM.





Top