YZ250 electrical issue, won't rev up.

Motor has been running well, just finished an area LLQ a couple weeks ago and following weekend race at Dade City. He got into a 1st turn pileup and 2 corners later pulled off the motor wouldn't rev and misfiring. Runs good and clean down low and soon as it gets into the power stuttering and falling off. It's not popping (out the pipe) or bogging down just doesn't rev up. Pulled the cylinder off powervalve cover and checked everything moves free. Jake knows when the powervalve screws up, the pin that sets in the springs on main shaft fell out a couple months ago. Took carb off removed float checked needle and all jets clean and clear. Checked the kill switch (unplugged) no change. Spark plug cap is tight and secure. The one issue that has me worried is I found some small metal filings on the magnetic pickup and inside the flywheel. The weekend after the LLQ we found a snapped off cylinder stud on the front left. I had to drill and tap because I broke 2 extractors, in this process the end of the drill bit broke off, the reason I know along with the small amount of filings was a tiny piece of the gold titanium bit stuck inside the flywheel about the size of sunflower seed. I had no idea this happened until I found the evidence and then found my cordless drill with the bit still inside it, you could see where half of the end of the bit was missing. The leading edge of the magnet on the flywheel has a couple small dings on it where it may have been pinched between the pickup and the magnet. Don't want to spend $500 on a stator and flywheel if there's a possibility I'm missing something.