Yes, my symptoms were ok start and idle, but it would cut out under mid/top power.  When I removed the head I found blackened bolts and head stay plates from the arching that was going on.  It was an a-ha moment.  I had a partial ground thru the bolt to frame connection but it is just not enough.

I also used 'throw-away' bolts to protect the threads.  Didn't think about the washers, but that is a good idea.  I will use this for future powder coating.