I asked because I am having the exact same problem
I have a 2005 Arctic Cat 400 4x4 Auto FIS with NO SPARK
I was out riding my 2005 Arctic Cat 400 4x4 Auto FIS and parked it for 5 minutes and then I had no spark.
Battery fully charged
Kill switch check and is perfect
New spark plug, new coil
I pulled the side cover and flywheel and magnets are perfect
Stator tested poorly, not bad, but I replaced it and the trigger anyway.
Here is the really big problem
From the day it broke down I have been getting high voltage 370 volts to the coil positive wire with just the key on and 390 volts with the engine turning.
According to the manual it should be 31v with key on and 130 volts turning.
I get the same reading and no spark with the regulator/rectifier connected or disconnected.
With the key on, if I go to attach the positive wire to the coil, it makes one high voltage spark and in a second or two when you touch the wire to the coil again it will have that same spank again.
Even with the new trigger I still get the negative voltage to the coil
What do I need to replace?