Need Help Fixing Simplicity 12.5LTH

Discussion in 'Mechanic and Repair' started by wyoming lawn service, Aug 22, 2010.

  1. wyoming lawn service

    wyoming lawn service LawnSite Member
    Posts: 108

    Guys,

    Need help fixing a 1990's Simplicity 12.5 LT 38" Hydro tractor. Tractor has low hours and had full professional tuneup at the dealer last year.

    Have two issues

    1) Front tire needs to be replaced. Has a tear in the side wall.
    Tips for replacing it at home? How do it do it myself?


    2) Tractor was running great last season after professional tune up/carb cleaning. Dealer said it was in very good shape. Unfortunately my it started acting up. My brother said he noticed he was having problems with the seat. When he was riding if he shifted around on the seat it was cutting out. They way he described it made it seem like it was the safety switch on the seat.

    Battery was replaced last year, new plug, carb cleaned, and wiring harness was throughly looked over by Simplicity dealer. I don't want to put the money into taking it to the dealer again. Need help fixing tire and non start issue on my own.


    When I last tried to start the tractor it had power and but NO CRANK. NOTHING. It didn't make any noise whatsoever.

    So should I jump the two wires together on the seat safety switch and see if it starts? If it starts that way, then I can order a safety switch and install it. If that doesn't work, then where do I look?


    The tire, figured I could jack the tractor up. Take of the rim, remove tire with screw driver. Place new tire on rim with screw driver and then fill it with air. Does this sound okay?

    Thanks!
     
  2. wyoming lawn service

    wyoming lawn service LawnSite Member
    Posts: 108

    Okay got tire fixed.

    Bypassed seat safety switch still no start.
    Ground on starter spins easily and gets hot. Tried to tighten, no luck. What now?
    Posted via Mobile Device
     
  3. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Posts: 2,231

    Pull the blower housing and disconnect the kill lead to the ignition coil. This should bypass all safety switches. Pull the spark plug wire then turn the switch to start position. If the engine turns over you problem is likely in one of the safety switches. If the engine is a Briggs, there should be only one wire to the starter and that is the cable from the solenoid, not a ground. The starter should be grounded through contact with the engine.
     
  4. wyoming lawn service

    wyoming lawn service LawnSite Member
    Posts: 108

    Sorry it is a Briggs and Straton Vangaurd 12.5. Twin cylinder.

    So the black wire running from the selonoid is a power wire not ground? I can wiggle it back and forth, i would guess that is bad! What does that wire do?

    The seat safety switch, I cut the wires and wired them together.

    So next step tomorrow will be take off the cover and remove the kill switch from the coil. Remove the plug wires and then try to crank it?

    If it cranks, then what?
     
  5. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Posts: 2,231

    If there is only one wire to the starter, that is the wire that powers the starter only when the switch is turned to start. What are the engine numbers? Model, type and code. Without any Simplicity ID number, I assumed the unit had a single cylinder engine. If it's a twin, the kill lead will have to be pulled from both coils. If it cranks, then your problem is somewhere else, likely one of the safety switches.

    What is the Simplicity model and serial number?
     
  6. wyoming lawn service

    wyoming lawn service LawnSite Member
    Posts: 108

    I will have to check the simplicity model number and b&s serial number. Here is a diagram of what the electronics look like though.

    simplicity diagram.gif
     
  7. wyoming lawn service

    wyoming lawn service LawnSite Member
    Posts: 108

    If you look at 33 on the diagram, you will see the wire that runs to the bottom of the starter. I tried to tighten the bolts, but I can rotate the wire between the nuts. Also after trying to start, this wire gets quite hot.
     
  8. wyoming lawn service

    wyoming lawn service LawnSite Member
    Posts: 108

    Here is the lower wiring harness image.

    The seat switch is 1 & 2. I cut the wire ends on this can connected them. Last year when tractor was running if you got off the seat it would say running. Eventually the tractor would no longer start. So I had thought it was simply the seat switch. Guess not!
     
  9. wyoming lawn service

    wyoming lawn service LawnSite Member
    Posts: 108

    Here is that image.....

    simplicity2 diagram.gif
     
  10. wyoming lawn service

    wyoming lawn service LawnSite Member
    Posts: 108

    Another question! Last year when it was fixed there was a tab I think on the coil that was bent. It was keeping the mower from starting. The dealer said it was arcing on the block. Could that be the kill switch you are talking about?


    Another side note, ignition was replaced last year by dealer.
     

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