Here's an update.For the first time in I dunno 8 freakin' months we had temps in the 70's.in southeastern Wisconsin.The warmer weather seems to have helped as the noise has stopped completely.I did hear it on cold start up, but just for a few minutes.I can live with that.May be the type or brand of fuel I used.It was Shell to begin with then I used BP.I don't know if there would be a vapor pressure difference? Possibly it took that long for air trapped to work it's way through?I always thought this engine had a fuel pump with a factory return line.Turns out the engineers call it a vapor return line,to prevent vapor lock in hot environments.A/C on Etc.It's supposed to allow air to dissipate in the return line before it can get to the fuel tank and disrupt fuel pick-up.Whatever it was/is we're good for now.
