GT 1100 no spark to plug

[dave in A.P. 4]

need some help guys, electrical problems are something i'm not very good at diagnosing. I went to start the tractor, starter engages,motor turns over fine but no spark to plug. I found a 2 pin connector ware the wiring harness goes under the shroud,pulled it apart. On run pos. of ignition switch my test light shows power to 1 pin, on start ,neither pin has power. Do the safety switches go thru the run or start circut? The engine won't even crank unless the clutch pedal is pushed in and the pto is disengaged. Is it a bad ignition switch?

[Road-Track 39]

:text-welcomeconfetti: From what you said about the starter turning over that means your interlocks and starter & starter solenoid work. And at least part of your key switch. The next thing to look at is power to the spark plug. Have you pulled the spark plug wire and connect it to another spark plug (grounded to the outer case of the engine) while cranking to see if you really don't have a spark?

That would be the first thing I would check. :eusa-think:

[Callen 64]

Does this still have the Briggs engine?

[dave in A.P. 4]

yes to RT and yes to Callen . I thought I had the problem solved at the ignition switch. When I pulled it and checked for continuity between B&S terminals, on 4 tries I only got 1 beep from my meter, I assumed the contact in the switch was shot, bought a new one & tried it at the dealer , had continuity every time I switched it from run to start.Came home & installed it, still no spark at spark plug. I guess its time to find a wiring diagram for this model & see if I can figure it out. Anybody got any ideas?

[Callen 64]

A bad seat switch can cause a no spark condition and will allow the engine to still turn over. To test your old switch, check for closed circuit on M and G post in run position, Should be open in run and closed in the off position. The 2 pin is charging leads. There should be a kill wire that is attached to a bolt in the carb area. Disconnect the wire and check for spark. If there still isn't any you need to get under the shroud. Are you setting on the seat or have some weight on it to set the switch when checking for spark? I just went through that on a c121. Set on the seat and had plenty of spark.

[TT-(Moderator) 1,169]

Are you setting on the seat or have some weight on it to set the switch when checking for spark? I just went through that on a c121. Set on the seat and had plenty of spark.

Unless you have something wired wrong, there is no need to be on the seat to have spark at the plug. That part of the circuit is only activated if the PTO is engaged.

[Callen 64]

Terry, I'll have to look into it then. It's a new to me tractor.