stlliberator

iTrader: (1)

I have 502 mpi motor that we have converted to a carb set up with a 500hp carb on it. I just use the factory sea water pump fuel pump to feed the carb. It has 6-8 lbs of pressure normally. Well yesterday we were having a lot of fuel issues. Like the motor was running out of fuel. We would be running around 3800-4000 rpm and the motor would cough and sputter and die. Well I thought it was the water separator, so I changed that, with no diference. So I had my buddy watch the fuel pressure and it would drop from 6-8 to 0. I noticed that there was fuel and oil that were on the stringer right below the fuel pump. I have a feeling that the great merc designed pump has finally taken a dump. So what would you guys do..rebuild the pump? Buy a new one, or go to a electric fuel pump...I need to have it done in two weeks...

mickeymcclgn

iTrader: (1)

I had a similar issue earlier in the year, I didn't catch it in time and trashed the cam that the pump rides on. Mine wasn't salvageable so I had to replace the whole assembly.

If it was me id take it apart see if the pump cam is in good shape and if it's the case id put a new fuel pump on it (the pump arm is probably ground down) and re seal it up. If not you're looking 500 or so for a new seawater pump and fuel pump combo)

FIXX

iTrader: (2)

+1..yep,,the section of the sea pump where the pump is is full of gear lube to keep the cam from wareing out..well over the years it fills with gas and thins out the oil then the cam wares out..cheap way out would be remove pump,replace the bearings and seals and fill with gear lube and install a mallory marine electric fuel pump..

stlliberator

iTrader: (1)

Can't I iust put a block off plate on the seawater pump where the fuel pump bolts on?

mickeymcclgn

iTrader: (1)

Absolutely, if you're going to run an electric fuel pump you can just block off the fuel pump area and run it as strictly a seawater pump.

stlliberator

iTrader: (1)

So let me get this right..its not the actual fuel pump that goes out..its the sea water pump that has the cam in it and fills with fuel and wears out...so replacing the fuel pump itself wont fix the problem?? Cause mine is leaking oil out of it.

FIXX

iTrader: (2)

if yours is leaking oil out of it then you most likely have bad bearings..those will go out and will not let the sea pump pump[ fuel....not only is their a cam on the shaft but theirs also a sleeve that rotates around the cam in the pump and that too wares out..merc makes parts to rebuild it..
2-of # 14
2-of #17
1-of #15
1-of # 16
1- of # 19 http://www.jamestowndistributors.com...t.do?pid=75061

you will need a power steering pully puller ,,snap ring pliers,bearing seperator and a press to remove and install all the parts in the pump..its real simple to rebuild...the parts to repait it will cos about the same amount to install a electric pump..

stlliberator

iTrader: (1)

So if I just block off the pump and put a electric pump in will the pump seize and stock pumping water too?

FIXX

iTrader: (2)

your best be is to remove the sea pump and bracket and all..remove the fuel pump,,drain the oil and gas out of the pump,,then remove the inpeller and housing and spin the pully..if you hear any bearing noins or if it feels rough then yes your going to have problems..if its leaking oil likr mentioned in the last pose then theirs issues with the pump..its simple to rebuld..takes less that a hour..that is if you have the rite tools..