I am just trying to make sure its my fuel pump before I do anything else. I noticed last night after I ran the boat for a little it wasnt wanting to keep running unless I kept pumping the primer bulb I thought it was the tank vent at first but it was fine. I thought maybe it was the primer bulb itself so I took it off put a new fuel filter in it and I cranked up the engine and the filter never got any gas to it. Took it back put the primer bulb on pumped up the bulb and the motor ran until It emptied the gas in the float then quite again. Im hoping its just the fuel pump just wanting to see if It could be anthing else. Thanks

The old fuel pumps would only last a year or so.. Most eveyone is putting a Low Pressure External Fuel Pump. (purchase at Napa)
You wont have to take off your old one.. Use both of them.

That should fix ya problem...


Uncle-J

I ran over 140 hours on a fuel pump so before you add the complexity of an E-fuel pump there are things to check. I have a step by step fuel system troubleshooting posted on another site but its down right now and will post it when I get home.

One of the first easy things to do is take a short fuel line and run it right from the fuel filter into a gas can at the transom and go run it. If it works fine, then its in the supply line somewhere. These fuel systems are low pressure and the slightest leak or bent fuel line etc... can cause a problem under load (i.e. it may run fine in the driveway but stumble under load). Primer bulbs are notorius for leaking, you can try it without one as the second step.

also saw a post the other day about someone who "upgraded" their fuel line up to 3/8 and it was too big for the pump and bulb handle. couldn't move that much fuel and then left air in the line... so ck your fuel line sizes..

If you weren't having the problem before, probably not it, but thought I would throw it out there...

Yeah it was running great then about 3 days ago when I took it out it was starting to not want to idle I would have to keep on the gas. I think cause the cam was turning fast enough to get the pump to work a little. It was getting worse after that yesterday it wouldn hardly go on top end anymore. I knew somthing was wrong. I double checked the hose connections and the tank vent and it all looked good. I pulled the pump and when i press down on it it doesnt seem like it is creating a vacume. Pretty sure its the pump. iI can get the motor to run with the primer bulb but have to keep pumping it.

The Baffle inside of your primer Bulb may have collapsed, take your fuel line off of your tank and pump the bulb, if it is blowing air back into the tank then your bulb is bad, also there is a hose that goes down into the tank off of the plastic piece that your fuel line hooks too, unscrew that whole assembly out of the tank and see if that hose is split, if it is then you are getting air in your fuel line.

Had this same thing happen to me. Hope this helps out bro!

I am almost 90% sure one of these 2 things is your problem!

Here you go:

You shouldn’t really need an external pump if you have a fuel delivery problem which shows up under load.
Check your connections to make sure there are no obvious leaks, Quick disconnects at the tank and the motor are notorious for this. Make sure you have fresh fuel.

Process of elimination things you can check to isolate a fuel delivery problem-
-Remove your primer bulb and run your source line to a fuel can sitting at the transom, if your tank is there, run a short line from filter right into the fuel to eliminate the primer bulb and tank/pick up tube as the source of the problem.
-Ensure you don’t have a kink in the supply line from filter to fuel pump, depending on how the inlet line is clamped it can cause a restriction, make sure you have a gentle curve in the line into the fuel pump. A kink will cause the carb to starve at higher RPM under load. (People that do alot of volume in motors see 1 in 10 that have a kink from the factory and it will prematurely cause fuel pump failure)
-Run your line/filter straight to the carb and use the primer bulb while running (bypassing the fuel pump). If the issue does not occur you have isolated the problem to the supply side.
-Check to ensure your lines to and from the fuel pump are clear. With the motor cooled down- Disconnect the fuel line at the carb and ensure you can pump the primer bulb easily and get a steady stream of fuel at the point it would connect to the carb.
-You can check your fuel pump by connecting your fuel line with primer bulb directly to the carb. Run a separate line from a fuel can into your fuel pump and out of the pump back to the can. Run the motor using the primer bulb to keep it running and if your fuel pump is operating well you should see a steady stream of fuel going back into that fuel can. If the pump is good, concentrate on the fuel lines from filter to pump and pump to carb to ensure there’s no degradation in the lines causing a restriction.

I've had a bad primer bulb also. If you have a clear fuel filter, see if it bubbles at all when running. If so, you have an air leak somewhere.

I tried couple of the things you suggested and I think I have isolated it to the fuel pump I can keep the motor running with the primer bulb and no fuel is spitting out of the pump when Iam running the motor I made a direct line to the carb and I can keep it running like that. I checked all the fuel lines and connections cant find a kink or bend anywhere in the lines everything seemed ok. Im thinking I need a new pump always somthing I guess

I have run into the same problem, but only with my vertical motors (not sure why) my Mod'd MB never a issue. I just added a inline E-pump nothing more then 3psi, also if its a push pump, mount close as possible to the tank or you will shorten the life of the pump. I've been running a Mr. Gasket for 35 hrs without a issue to this point......Knock on Wood

Fowl,
You got it fixed?

yeah did you get it fixed, this is wearing on me, hey also i am not running a fuel pump and not having any problems, so why are some of you guys running a fuel pump? Is it better?

Got the problem fixed I ended up putting the Electric fuel pump Uncle J mentioned gettin It mouted nice to the boat I wired it in to my key switch so that the pump only comes on when I turn my key on. The guy at napa said thats the best way that way its not always on. It seems to work great the motor started right up and stayed running Im goin to take it out on the river tonight and test it some more but pretty dure I got it fixed.Thanks for all the quik help much aprreciated. I might order the stock fuel pump anyway just to replace but so far so good

Well i meant electric fuel pumps, why do you guys run electic fuel pumps

I dont want to run one I just dont like to be down so I have it for a back up now. i ended up getting a stock fuel pump today so I put that back on and took the electric one off. iam going to keep it in the tool box so if the stock one goes I can still run the motor. I curious to as to why guys switched to it

I switched to a facet fuel pump months ago and i can put my fuel tank where i want it, run 1/4 or 5/16 line, use quick connects and dont have to watch for all the problems of a mechanical pump. Hell how many cars have you seen on the road made in the last twenty years running mechanical pumps?

Fowl,
Glad I could assist..


Uncle-J

ok i gotcha

The fuel bowl has to maintain a given amount of fuel in order to allow the venturi effect to pull the correct amount of fuel from the bowl. Preventing the correct amount of fuel in the bowl definitely affects the performance of the motor from idle all the way to wide open throttle. I have an electric pump on a stock 35 GD surface drive along with a fuel pressure gauge and a holley low pressure fuel pressure regulator. I have altered the fuel pressure from 0.5psi to 2 psi and from 0.5 to 1psi my stock motor will start to misfire after about 20 seconds of wide open throttle operation when in the water, however when I increase the pressure from 1.25 to 2psi the motor quits misfiring altogether at WOT (wide open throttle). The weight of a greater amount of fuel in the fuel bowl assists the vacuum of the motor in pulling in the correct amount of fuel. In other words if the volume of fuel is too low in the bowl the weight of the fuel cannot assist the vacuum in pulling a sufficient amount of fuel and your motor will let you know by misfiring at certain RPM especially under a load.

2 years on the stock pump feeding a S&S Super E for 1/4 of that time and no issues. I also don't run a fuel/water seperator, which I feel may be the demise of the stock pumps.