It seems that it's running too rich, as I get a fair bit of gray smoke out of the exhaust as it's stumbling. (mechanics.stackexchange.com)
First every 20 seconds or so then gradually increasing frequency over the course of 30 minutes until it was every few seconds, blowing gray smoke, and eventually stalled out. (mechanics.stackexchange.com)
I may opt for black or gray smoke instead, but still, great food for thought! (lovegrowswild.com)