Scag / Kohler engine has me stumped

[aloha]

Well, that is unfortunate. Keep us posted. There's nothing quite as much fun as an electrical problem.

 

[TRUBBLESHOETEN]

Well, that is unfortunate. Keep us posted. There's nothing quite as much fun as an electrical problem.

TO ALOHA: Just thought I'd give it some time to prove itself. Anyway, after all the work of the ign switch, module, relay, flywheel, stator, voltage regulator and battery and after it crapping out with the same problem that it had before all the work (and by-the-way most of the electrical parts that were replaced all eventually checked out to be no-good; except for the ign. switch). off it went to the dealer.... where, after replacing the fuse, and after checking all my work the mower did not exhibit one bit of trouble and worked flawlessly for them. They could't find one thing wrong with any of my workmanship! So happy I am art g

 

[TRUBBLESHOETEN]

B U T S T I L L B E W I L D E R E D!!!

 

[Spindles187]

So just been searching online and have same issue with my 2013 Scag Tiger Cat.
It starts when in the start position, but shuts off once you release it from start to ON position.
Bought a new ignition switch and not the problem, changed the fuses hoping that it work work then, but nope still same issue.
Not sure if maybe it is the electronic module.

Thanks

 

[My Hoe]

I didn't read the whole thread, but from my automotive experience, I've read that classic cars ('60's? '70's?) had a "step down circuit" (my words--can't remember the term) that lowered the 12v going into the coil, when CRANKING, to something like 6-7v, for running--I think to prevent overheating the coil.

I'm wondering if modern lawn equip. could still be using 40 year-old technology in this regard, but instead of your "running voltage" stepping down to a less-than-12v value, it's just going away.

Having said that, I believe I read that you replaced the ignition switch, which would seem to eliminate the above, as a possibility, EXCEPT that I don't know how that "step-down" in voltage was accomplished. IOW, maybe it was done somewhere other than the ignition switch?

You could try googling this issue, in the automotive area, and see how those guys diagnose and fix problems with this design, if you could find such a discussion. (I read about it in a Hemmings publication, but I don't know if you can read those, online, w/o a subscription. But I'm sure there are other articles out there).

Good luck!

 

[CCWKen]

Actually, it was the other way around. FULL voltage was applied to the coil during Starting. A reduced voltage was used in Run position. This was accomplished by a physical resister (mostly Chrysler) or resistance wire (Chevy, Ford) in the ignition circuit. In the Start position of the switch, this resistance circuit was bypassed since cranking voltage of the battery was already reduced by the starter draw.

Added:
Perhaps you have it right. After re-reading your statements several times, I'm still confused.

The resistance circuit was employed only in the Run position of the switch. The resistance circuit was NOT in the switch itself.

 

[My Hoe]

Actually, it was the other way around. FULL voltage was applied to the coil during Starting. A reduced voltage was used in Run position. This was accomplished by a physical resister (mostly Chrysler) or resistance wire (Chevy, Ford) in the ignition circuit. In the Start position of the switch, this resistance circuit was bypassed since cranking voltage of the battery was already reduced by the starter draw.

Added:
Perhaps you have it right. After re-reading your statements several times, I'm still confused.

The resistance circuit was employed only in the Run position of the switch. The resistance circuit was NOT in the switch itself.

No, you're right--I had it HALF-right.

I should have stated:

"I've read that classic cars ('60's? '70's?) had a "step down circuit" (my words--can't remember the term) that lowered the 12v going into the coil, when RUNNING (not "CRANKING", as I originally said--no wonder you're confused! LOL) to something like 6-7v, for running--I think to prevent overheating the coil."

But since you've reminded me this "step-down" was accomplished OUTSIDE the keyswitch (and KUDO's for your brand-specific knowledge!), IF that same idea is being used in the OP's Scag, and IF that "RUN" cirucuit is malfunctioning, conceivably, that could explain the OP's symptoms, right?

And thanks for the refresher--I obviously needed it!

My Hoe

 

[murphy1244]

No, you're right--I had it HALF-right.

I should have stated:



But since you've reminded me this "step-down" was accomplished OUTSIDE the keyswitch (and KUDO's for your brand-specific knowledge!), IF that same idea is being used in the OP's Scag, and IF that "RUN" cirucuit is malfunctioning, conceivably, that could explain the OP's symptoms, right?

And thanks for the refresher--I obviously needed it!

My Hoe

GM used a nickel wire for the run circuit and Dodge used the infamous ballast resister.

 

[My Hoe]

GM used a nickel wire for the run circuit and Dodge used the infamous ballast resister.

Cool--I didn't know that--now I know where to get some real nickel (for whatever use it might serve--experimenting while brazing, perhaps?) the next time I get to the junkyard. Amazing what you can learn here! :thumbsup:

 

[murphy1244]

Cool--I didn't know that--now I know where to get some real nickel (for whatever use it might serve--experimenting while brazing, perhaps?) the next time I get to the junkyard. Amazing what you can learn here! :thumbsup:

That was on the old points cars and was dropped when they started using the HEI