Need some help..my sons 85 with just rebuilt(top end -everything), while he has been breaking it in..it has been fauling plugs like crazy. The mix is 32-1,going to change to 40-1. see if that helps..but here is the prob if I put a new plug in.....it fires right up..runs for about an hour or more then "bogs" down and quits...Put another new plug in..same thing.. The plugs come out a little oily...try to clean them and use again but now it wont fire or do anything. Should I pull the top end apart again???