1999 Seadoo GTX Limited Not Getting Fuel

[dmontero]

Hi Everyone, first post here. I just bought a 1999 Seadoo GTX limited. Compression is good in both cylinders. The engine sparks and turns over but doesn't start. The previous owner told me that he thinks it is the MPEM but from what i have read, a spark generally means that is not the case. Fuses are all good.

What I do know is that the engine is not getting any fuel. The fuel filter is completely dry when i unscrew it. The lines are dry as well. The lines are the old original ones so I am replacing these this weekend.

What is weird is that I disconnected the main fuel line that comes out of the fuel selector and goes to the carb/motor and put it in a jerry tank on the side and it still didn't pull anything. This model does not seem to have a fuel pump per the manual. Sprayed some start fluid in and that didn't do anything.

The fuel line routing at the dual carbs seems a bit weird? There is the fuel line into the bottom of the carb. Then there is a "T" shape nipple on the front carb. The back part of the T connects the front carb to the back carb. The front nipple of the T is empty though - the manual doesn't really provide clarity of this. Could this be an issue? There is another nipple on the front carb that 90's down and returns to the fuel tank. I have ready that there is a fuel accelerator pump on the carb, could that be the issue?

Kind of confused on what to do next as my gut is telling me that new fuel lines won't fix this. Any help is appreciated!!! Thanks!

 

[nsoley]

In regards to your Jerry tank… that is odd. What you essentially did was put a direct feed of gas to the carb; this leads me to believe the fuel pump in the carb is not pumping gas.

How’s the pulse line? Don’t want this clogged… this is the mechanism that provides suction and pressure to the fuel pump in the carb.

 

[dmontero]

Thanks for the response - If the accelerator pump is bad, is that an easy swap? So I am struggling to understand which line is the pulse line and which is the return. What does the pulse connect to? I have swapped a few fuel lines around but nothing seems to do the trick. See below for a photo of my front carb.

1. The fuel in is connected correctly on the underside (not visible)
2. Then there is the empty nipple that 90's down. initially I had the return line connected here. Is this the pulse or return? If it is the pulse, does it connect to anything?
3. Then on top you will see a T. The T splits off to the back carb. Then I connected the return here. When I got the ski, the return was connected to the nipple that is empty in the photo.

The seafood manual diagram doesn't accurately depict this duel carb so its tough to know what is what!

 

[etemplet]

Swapping lines around is not gonna solve the problem. They have to be installed properly. The accelerator pump will not prevent the ski from starting. Here are a few pictures of the 951 Carbs. Most pictures are before I rebuilt that carbs. Might ease your worry about connecting the hoses.

From my perspective, I do the entire fuel system including draining and cleaning the fuel tank. You don't have to go that far but I don't like chasing problems. Also a Mitey-Vac vacuum pump you can pull a vacuum on the system and check for leaks or plugs. Never trust the fuel valve. Take your time and be meticulous and thorough. Good Luck.

NOTE: that red circle in the first pictures is the accelerator pump line. There is a brass orifice in that line and it is very small. Be aware of that and don't lose it.

 

[dmontero]

awesome photos - I think I have all lines installed correctly.

Yesterday I pulled the return line off the front carb and pushed some air through it. I read on line that fuel should be forced into priming the carbs come out of the return nipple. It did finally fill up the fuel filter so I know its getting OUT of the baffle and OUT of the fuel selector. No gas came out of the return nipple but rather it came flowing back out of the return line I was pumping air through (presumably after it hit its road block). I installed a transparent blue gas line for the accelerator pump line becuase I felt like the previous one was kinked - NO gas was observed in that line.

Questions:
1. Should gas be coming out the return nipple if I pump air into the return line to the tank?
2. If so, could it be possible if I have some sort of blockage in the carb up stream from the accelerator pump fuel line since no fuel was observed there?
3. Can you circle where the pulse line is on your photos?

 

[dmontero]

This is my carb (front). The hose going off page right is the return that I blew air through. Is the pulse like the empty nipple that aims downwards?

 

[etemplet]

Yes you have correctly identified the pulse line. I'd put a clean hose on that connection and do the suck me blow me to make sure the fuel pump is working. Just a puff both ways. If it is moving freely back and forth then there is a pretty good chance the pump is drawing fuel from the fuel Valve. Did you check for a leaking fuel valve or water separater gasket? I pull a vacuum on the system with the lines pinched near the fuel baffle. Are you using 5/16" fuel lines in the appropriate places?

 

[dmontero]

Ok I will put a line on the pulse nipple now and try that. The transparent fuel line at the accelerator pump is bone dry though. It was also dry when I pushed air into the return line - so I do not think the pump is getting anything.

The fuel valve isn't leaking. I bypassed it and run my trouble shooting with/without it many times now and no difference.

Water separator gasket is also good.

Where do you pull the vacuum from? The return line?

The fuel lines are 1/4" and were replaced by the previous owner. I think the only 5/16" is up between the selector and the filter/separator. Not sure why this line is bigger than the rest but I didn't think it was an issue.

 

[dmontero]

Update: did the test on the pulse line and I was not able to move freely both ways

 

[dmontero]

Etemplet - does that pulse nipple sit empty? OR does it need a hose to the engine? struggling to find good info on it in the manual or online and it seems weird that it wouldn't connect to anything...

 

[etemplet]

The connection for the pulse line is under the carbs near the PTO end of the engine. There are two connections under the engine near one another. One line goes to the rave valve solenoid and the other goest to the pulse nipple on the carbs to operate the fuel pump.

 

[dmontero]

THIS is what I have been looking for! I will let you know how it goes...

 

[etemplet]

The fuel feed line is at the bottom of the mag carburetor. You can see that line in the picture (vertical). Don't mess with the return line, leave it connected.

CAUTION: Make sure your choke is connected and working before you start this engine. They will run away and the best way to shut them down is pull the choke so make sure it's working.

 

[dmontero]

Alright so a took the carb out. Took it apart and cleaned it however it was already in pretty good shape with new gaskets/diaphrams (I think the previous owner rebuilt). Put the carbs back in and connected the pulse line which was not previously connected.

Fuel is definitely pulling now which is great but it’s still not firing. I sprayed some starter fluid in the carb and no dice.

The previous owner said that he hadn’t been able to start it and he thought it was a computer problem. Everything I’ve read says that the mpem is good if you get the two beeps and a spark (I’m good on both).

So I’m not sure what to do now - could the spark not be timed right with the pistons?? That’s all I can think of

 

[etemplet]

Verify you have the correct spark plugs and check the timing. I've ever electrically checked timing on any ski. One time I did have the incorrect mag flywheel installed. Strange but that is what was in the ski when I bought it. LOL If you have a timing problem that is the place I would look. The skis are very simple. If you have spark and fuel it should run. Good Luck

 

[dmontero]

Ok I’ll check it out tonight! I know sparks are good as I just replaced them.

Even if the timing is off would it still at least fire (just not perfectly)?

Should I try starter fluid again in the carbs or gas/oil in the pistons? I’ve read mixed opinions online. When I tried started fluid yesterday it still didn’t fire

 

[mikidymac]

No, never use starting fluid in a 2-stroke. Mix up a little premix if anything.

 

[etemplet]

Ok I’ll check it out tonight! I know sparks are good as I just replaced them.

Even if the timing is off would it still at least fire (just not perfectly)?

Should I try starter fluid again in the carbs or gas/oil in the pistons? I’ve read mixed opinions online. When I tried started fluid yesterday it still didn’t fire

Verify timing is spot on, You could have a sheared key on the crank, bad wiring, any number of issues.
Put a 1/2 cap of premix in each cylinder intall the plugs and wires. It should try to start or give and indication it wants to.

 

[dmontero]

Update: getting fuel, it was definitely the pulse line!!

Now I am getting no spark so can't quite think about timing yet... going to start a new thread for that one

 

[etemplet]

I have never messed with the electrical aspect of timing on these skis (using a timing light). It was always a component or fuse or plug or wire that gave me spark issues. Is your beeper working? Some spark issues are dependent on the Computer recognizing the key and can sometimes be solved by reinserting the key. Check for power to the rear coil and check the fuse in the rear electrical box.

 

[dmontero]

beepers good and fuses are good - see my new thread here
1999 Seadoo GTX Limited No Spark

 

[racerx3110]

We had crank and spark issues, here is what we did to get our solved:
99 Seadoo GSX Limited won't crank/no spark