I have a 1997 mercruiser 7.4 carb with the fuel pump mounted on the raw water pump. Does the raw water pump shaft that moves the fuel pump lever have what looks like a bearing or it's suppose to be fixed like a camshaft? Its looks like its loose.
Hi First things first, get yourself a good repair manual and go from there, but the carb engines I have worked on, the fuel pump is mounted on the right side of the block by the raw water pump and the fuel pump is driven by a shaft that is driven by a centric on the camshaft, and have no bearings,I could be wrong as it has been a while since I worked on a 7.4 ltr, but try the repair manual as I said and go from there good luck.
Thanks for your reply. On 7.4 and 8.2L the fuel pump is mounted on the raw water impeller pump, so it's different from small block. As for the losse "bearing" I already verify my doubt on a Seloc repair manual, but is does'nt specify this information. If you could get any other info let me know.
I will try to find out that info for you, I don't work on the BIG blocks as I'm 6,2 and 230 lbs so I can't fit into the really tight spots on many of the boats with big blocks in them I let my other mechanic get in there, being the boss has it's perks :-)
I worked on a boat last year that had a failure of the fuel pump (mounted to the raw water pump). When the pump was removed the arm of the pump was damaged and the bearing inside the raw water pump looked scored and wobbled as you say like it was loose.
I replaced both the sea water pump and fuel pump. The new sea water pump had the same looseness to the bearing, so it is like a bearing and not like a camshaft.
Remember to fill the cavity for the fuel pump with some oil. There is a drain plug (slotted) on the side.