Thread: 75 HP Mercury

#2 is pump kit, that is where I would start. Also if your motor is not oil injected see notes on filters it might have if not injected.
Mercury Outboard Parts by Year (Mercury, Mariner, Mark, Force, Chrysler, Sears, SportJet) Mercury Outboard OEM Parts Diagram for FUEL PUMP | Boats.net
You might do a search on that part number and find kit a little cheaper but these folks are usually in the ball park price wise. Did you by chance pull plugs and check them?

#2 is pump kit, that is where I would start. Also if your motor is not oil injected see notes on filters it might have if not injected.
Mercury Outboard Parts by Year (Mercury, Mariner, Mark, Force, Chrysler, Sears, SportJet) Mercury Outboard OEM Parts Diagram for FUEL PUMP | Boats.net
You might do a search on that part number and find kit a little cheaper but these folks are usually in the ball park price wise. Did you by chance pull plugs and check them?

Thanks Cray! I forgot to mention that I replaced the fuel pump diaphragm back in March when I replaced the the fuel lines. At that time, I could not keep the ball pumped - it would lose it's prime after sitting for 2 to 3 hours. Diaphragm replacement fixed that issue. Boat still ran good before this, but you had to remember to pump the ball before you tried to start.

As for the plugs, I have not removed/inspected yet. I didn't change them this year, but did last year. That is definitely one thing that will get done during this event. One other item that I forgot to mention - while at the dock, I throttled up while out of gear. Max RPM was 2K at WOT, and it had a lot of smoke - like oil smoke. And FYI, it is still oil injected (separate oil tank).

Originally Posted by KokomoTerror

Thanks Cray! I forgot to mention that I replaced the fuel pump diaphragm back in March when I replaced the the fuel lines. At that time, I could not keep the ball pumped - it would lose it's prime after sitting for 2 to 3 hours. Diaphragm replacement fixed that issue. Boat still ran good before this, but you had to remember to pump the ball before you tried to start.

As for the plugs, I have not removed/inspected yet. I didn't change them this year, but did last year. That is definitely one thing that will get done during this event. One other item that I forgot to mention - while at the dock, I throttled up while out of gear. Max RPM was 2K at WOT, and it had a lot of smoke - like oil smoke. And FYI, it is still oil injected (separate oil tank).

what type of fuel line did you use ??? and is the color of the fuel line grey ???
reason for question I had a 1996 75hp mercury did the same thing , the inside of the fuel
line was breaking apart clogging it and starving the engine of fuel !!!! and it was a new fuel line as well color was grey !!!!
went to a auto parts store and bought a fuel oline rated for ethanol problem solved !!!!

The fuel line is grey. I bought it from a marina - supposed to be good fuel line. I can guarantee (as long as the pumps are truly ethanol free) you that I have only used ethanol free gas for the last five years. I will take your advice and look at the hose as that would be a pretty easy fix.

First thing you need to do is pull plugs and check to see if they are saturated with oil. Sounds almost like it could be over oiling through your injection pump. Another thing you could do is borrow a remote tank and hook to it and see if it runs better.

if you take off the end that goes to outboard motor look on the inside if it has a clear inside tube that more than likely the problem !!!here is a article on the issue !!!!Outboard Fuel Line Problems | The Boat Galley

STRMWALKER - thanks! Good article. Interesting that it happens with ethanol free gas as well. I will be working on it tonight, so hopefully, I will find something "easy" like fuel line. I will start there and go ahead and change plugs.