2000 GTX Fuel Pump

[RJO]

I have a dumb question.
Does my 2000 Millennium GTX (not DI) have an electric fuel pump in the tank. If so can the pump alone be replaced. I know it has the fuel pump sending unit in the tank, but is there a replaceable pump in there? Or do I need to replace the whole unit on this one.

It started with the Seadoo not running well and I could nurse it with the choke to keep it running, only 3000 rpm. I figured it was the carbs, since they hadn’t been rebuilt in 15 years. I rebuilt them and replaced the gray fuel lines from all that I saw and read. I was surprised the fuel lines were clean and the filters in the carbs were spotless. I did find that there was a hole in the pulse line under the carbs.

After rebuilt carbs and new hoses it still had the exact same problem and I could keep it running nursing it with the choke. So there were absolutely no changes.

Then I decided to drain all the gas and put in new gas. This solved the problem for a little while. It ran rough in he beginning, probably flushing the old fuel , then it kicked in and ran great for about 20 minutes and died in the middle of the lake.

I pulled the fuel line from the carb and turned it over to see fuel was coming through the hose and it wasn’t. Shouldn’t fuel be pumping from the hose?

Everything I find about the pump replacement is on the GTX DI

 

[RJO]

I have a dumb question.
Does my 2000 Millennium GTX (not DI) have an electric fuel pump in the tank. If so can the pump alone be replaced. I know it has the fuel pump sending unit in the tank, but is there a replaceable pump in there? Or do I need to replace the whole unit on this one. Can I test it by hooking up power?

It started with the Seadoo not running well and I could nurse it with the choke to keep it running, only 3000 rpm. I figured it was the carbs, since they hadn’t been rebuilt in 15 years. I rebuilt them and replaced the gray fuel lines from all that I saw and read. I was surprised the fuel lines were clean and the filters in the carbs were spotless. I did find that there was a hole in the pulse line under the carbs.

After rebuilt carbs and new hoses it still had the exact same problem and I could keep it running nursing it with the choke. So there were absolutely no changes.

Then I decided to drain all the gas and put in new gas. This solved the problem for a little while. It ran rough in he beginning, probably flushing the old fuel , then it kicked in and ran great for about 20 minutes and died in the middle of the lake.

I pulled the fuel line from the carb and turned it over to see fuel was coming through the hose and it wasn’t. Shouldn’t fuel be pumping from the hose?

Everything I find about the pump replacement is on the GTX DI

 

[JeremyD615]

There is no pump in the tank on the carburetor skis. The fuel pump is built into the mag side carb, and is operated by that pulse line that you had the hole in. I would double check that line again first. If it is loose or kinked, your fuel pump won’t work...

 

[RJO]

Thank you
I pulled the cover on the carbs and checked it. Hose clamps are on, and there no kinks. It has a nice smooth curve.

Any other ideas?

So the pump in the carb is sucking the fuel from the tank?

 

[POPPS]

I may be way off base here, but the pulse line draws fuel in from the filter/separater. If you remove this line,/the in line, the pulse line/fuel pump has nothing to draw from.

you may want start at your fuel pick up at the bottom of the tank, remove the reserve line, and gently blow thru the reserve line, not hard, the filter screen can blow right off. Make sure you remove the gas filler cap first, so the air has somewhere to go. Oops, and before you start this move, check that your fuel separater is full. This is going backwards, sorry, checking the fullness of your filter shud be your first check.

Between your fuel pickup, and the fuel filter, is the fuel on off valve, they can get soft and spongie over time, and can cause many intermittent or constant fuel starvation symptoms (and engine seizures). Actually, if your filter is not full, you are in luck, and have ruled out removing and going thru your carbs.

 

[JeremyD615]

Yes, the fuel gets pulled from the tank by the carb mounted pump. When you rebuilt the carbs, did you remove the adjustment needles and make sure to get the transition ports spotless? I’m thinking you’ve got some corrosion or funk clogging those internal passages somewhere...

 

[RJO]

I did remove the needles and blew cleaner through them. The jets were clear.
Like I mentioned, I couldn’t believe how clean the carb, filters and lines were when I opened everything up.

It’s strange that it ran for about 15 minutes very well. I had the needle valves opened a little more than 1.5 turns, so it wouldn’t be too lean, then I was going to adjust them.

I see there’s a pump test in the manual I will do tonight.

 

[etemplet]

Did you replace the fuel valve on the side of the ski? If you are not getting fuel to the carb I'd check there. Also check your filter for leakage because that will cause problems also.

When I get a ski I pull the fuel tank most of the time and replace all the lines, make sure they are connected properly then I pressure test the system twice. Once on the "ON" side once on the RES Side. It is a lot of work but when you get the ski running well it stays that way.

Another thing is to make sure your oil lines are not brittle and your filter is clean. Take some time and give it a good once over. Good Luck !!

 

[JeremyD615]

Having to nurse it with the choke to keep it running is a sign of being lean. The fuel selector should be replaced if you haven’t done it already. Don’t try to clean it, as they’re cheap and the solvents tend to make them worse.

I would also replace the o ring on the water separator, as it is a common place for leaks.

The third place to check is the fuel pump itself. It’s not common, but I’ve had issues with fuel pump gaskets and diaphragms not sealing well and leaking air as well.

 

[RJO]

I’m on it, I need to order those things, local shop in DFW said selector was discontinued.
I was careful and made sure everything was seated properly.

 

[mikidymac]

No, you have no in tank fuel pump on your ski.

The pump is part of the front carb and is powered by the vacuum line to the engine cases.

So if you pull the inlet hose from the carbs you will not get a flow of fuel from the tank.

1. Did you use only Genuine Mikuni parts including needle and seats to rebuild the carbs?
2. Did you follow the Carb Rebuild Thread sticky?
3. Did you replace the fuel strainer or at least the o-ring?
4. Did you replace the fuel selector?
5. Did you check pop-off and leak down on the carbs?

 

[LikeabossTM]

You can also try running with the fuel fill cap cracked open a little as well. If your tank breather vent is plugged that might explain it running well for 15 minutes before the vacuum in the tank from the departing fuel volume becomes too great for the feed pump to overcome with suction.

 

[RJO]

I followed the rebuild thread and different YouTubes and did all of those things.
Ordered the fuel selector and strainer o-ring. There wasn’t an O-ring in there. I haven’t checked that in years and it ran fine before. I have owned it since 2007, never looked for the o-ring, and it’s not stuck up on the housing either.
I will also check the venting, that makes a lot of sense.
Waiting on parts now.

Thanks y’all for the good input, I will get this fixed soon. So many times it is just something dumb overlooked.

 

[RJO]

Pulled the fuel sending unit, everything is clear and the filter is clean.
Vent line is cleat to the Y and both vents are clear.
Pulse line from the engine is pulsing, when I turn it over.

Shouldn't the carb inlet be sucking when when the engine is turned over and the pulse is hooked up?
It isn’t sucking.

 

[JeremyD615]

Yes, it should have some suction there. Have you pulled the carb and checked the fuel pump diaphragm for liquid on the pulse side?