have you tried bleeding lines yet?
most require priming after allowing any air in to the fuel system
find a downloadable service manual if you don't already have one this will explain the process step by step. it's usually really easy. (loosen one bolt and pump with a little button) i think the 4-107 has this little button right above the fuel filter cup on the starboard side of the block
"who za sheet is kingsley zissou"...claus R\V Bellefonte