I hope you have a service and repair manual.
One would think that since the VSG-411 engine went into thousands of fork trucks, skid steers and generators in the US parts would be readily available.
Alas, I have discovered they are not.
I have however had good luck searching eBay, Europe for many of the things you just cannot find in this country. They used these engines in Midget racers in England and Spain. Ford also used them in several small cars there that Americans had no interest in. It seems bigger is better here and since we have always had fuel about half the price or those in Europe, and they make an effort to keep things running instead of throwing them away and buying new...need I go on?
I was plagued with an intermittent and no spark situation with my 542B for 3 years. I took it to my dealer for the 1000 hour maintenance running great and when they were done it would only start and run at the lowest idle setting or would not start at all. If it did start and you gave it any gas it would backfire through the carburetor or die, still with no power. Maybe coincidence, who knows. They messed with it for 6 months cost me about 600 bucks in parts, I refused to pay for labor after the initial service charges or it would have been in the thousands.
After 6 months they told me to come and get it, they were done. THANKS A LOT FELLAS!!
I had several people look at it over the course of the next 2 years. Checked cleaned and replaced so many electrical connections I was ready to junk it.
The only reason I didn't was my wife would not use the 743 or 510 because they were too big and she was chicken. She loved that little 542 and she insisted I get it running. I happened to be in a town about 30 miles away and started talking to an old guy about it. Did you check this, did you replace that, so on and so on. The only electrical component I did not replace was the ESC (the brain) so I searched and searched. I found one in Europe. $250.00 and $150 shipping...WOW. I bit the bullet and got it. Of course that did not fix it. SOB!!!
I talked to the old guy again and he said it had to be the Engine Speed Sensor (crank position sensor, or flywheel sensor some call it). It is held in by 1 bolt on the lower right side of the engine picking up a spot on the flywheel. I told him I replaced it but he said to get another one.
Turns out I got a bad new one and after replacing it again I had no issues. That is why I said maybe the dealer working on it and the failure happening at the same time may have been a coincidence.
The first one I got was an aftermarket one, the second one was an original Ford part, 4 times the money ($84) but it did solve the problem.
I have had one other electrical relay go bad since then and I will find out what it is called and let you know. I just don't remember right now.
I told you this long story (sorry about that) to make the point that your fire, while probably the issue or something related to it, it could be something as simple as the crank sensor or the relay I can't remember the name of.
It could also be the ESC or, I have also been told if the Engine Coolant Temperature Sensor fails you can get a no spark condition, but I do not know this for a fact.
The original Bobcat part number for the crank sensor is... 88BF6C315AC... a search of eBay did bring up several that cross to that number but you need to look at the shape and bolt location to be sure a part you cross will fit, if you end up going that route.
As I said before, I have a tested ESC if you have to go that route. I know it is good because I have had it in my machine to make sure I was sold a working unit, after I got it running right.
Good luck and please keep us informed.