EVO2 SR cutting out at WOT

Ok, I was so happy to be done with my scoot...got the midrange all cleaned up and all. However after putting some time in on it today, I noticed its cutting in and out during WOT. I thought it was the mixture so I have tried everything from a 125 to a 140 and still cuts out. Im gonna run and get a new plug but im pretty sure this ones fine. The other possibility is the ignition. Im still running stock...at 14K maybe it cant take it. Finally, I mentioned earlier that with my welded engine bracket for the rear facing carb, I had to use a ground strap. The frame was no longer grounded. The strap is about 12 inches long and is a 6 gauge amplifier type wire with eyelets on the end.

So here are my questions...

I see most end up with 135-140 main....should I try going leaner, below 125?

Or does this sound like symptoms of an insufficient spark?

Thanks

Oh yeah....this gas is like almost a year old....haha. Fresh gas might clean it up...the octane prob isnt high enough to burn correctly at high rpm.

im putting the 130 back in...sound about right for the main?