Yes, in the end it seems like it was a multifactorial problem. There were some air leaks and those got fixed but the problem persisted. There was also some gunk in the strainer that went from the fuel tank to the fuel pump. So Mr H thinks part of the problem was that the fuel tank was dirty. Then the fuel pump failed presumably because of trying to pump fuel through the gunked up strainer. So in the end he replaced the fuel pump, fixed all the air leaks and had someone come & clean out the fuel tank. Now everything works perfectly but we are not really sure what finally fixed the problem.

I may not have mentioned previously that this is a charter boat we own. So we don't see her all summer, she is busy earning her keep. So we don't really know, have not been on boat since May, we have had no reports of any engine issues. But sometimes we are surprised at the things people fail to mention after a charter. Mr. H finally had to resort to fixing everything at once because it was getting to the point where it was affecting the charter income.