Update: We think we fixed it. Moved the ground to a different place on the subframe but still intermittently cut out when warm. But subframe is not warm at all so didn't think that was the ultimate issue. Then put in a new plug (only replaced the boot before) and that seemed to have fixed it. Not sure if the original broken boot arc'ing damaged the spark plug or not but so far it's able to run for 20+ minutes with the fan coming on and off. Will ride around the neighborhood to test and hopefully hit the trails a bit this weekend for a full test. Also, what's the consensus on which tail tidy? Sicass? oem-XCW?