Seadoo 1996 GSX Flooding fuel

[Andrewdinsdale]

Hi guys,

This post rolls on from my last thread where I couldn't get my GSX running.

Now its had; a new ignition coil, 2 x carb repair kits plus 2 x new needle valves and seats & a solenoid.

Its finally running.

But when I try and start it, it will cough and splutter and not start, check the plugs and they're wet.

Turn the fuel off, and after 15-20secs of cranking it fires up, turn the fuel on and it runs lovely on the hose pipe for a good 10 minutes. Revs up, doesn't stall, idles fine (ready for a water test?) you'd think.

But stop it, try and start it and it won't start. Not until you turn the fuel off and crank it over for a good 20secs and it will fire up again.

Why would it be flooding if its had new needle valves and seats? + needle valve spring etc.

I think everyones going to say have you checked the pop off pressure but after doing hundreds of carbs previous to these if I put new needle valves and seats in they have never caused an issue. By the way, these were genuine 1.5 mikuni needle valves and seats.

Only thing I have done that isn't standard is fitted a primer bulb off an outboard inline to help draw the fuel through the new fuel line that I installed. (My local seadoo dealer told me this was fine to do and fine to leave in). Is that right?

Any info appreciated. (Sorry for the length).

Thank-you.

 

[Andrewdinsdale]

I have just put the original springs into the carbs, balanced them properly and it seemed better.

Now I'm having the same issue as before, I've read somewhere about the grey tempo fuel lines- I still have these so I am going to try changing them. Could this be my issue?

 

[Cliff787]

Congratulations on getting it up and running!

I know it was a frustrating path. But you finally got it there! So great job!

Leaving the Primer bulb in is fine. I use a primer pump. But both work the same way.

Maybe check the vent lines. They could be clogged with debris and causing the tank to pressurize and send fuel to the carbs and cause the N&S to pop off. Thereby flooding the engine.

...and PLEASE PLEASE PRETTY PLEASE. Change those grey Tempo lines out ! You'll be doing a motor rebuild if those lines aren't changed out. So all of that work you just did will be for nothing as the fuel lines breakdown internally and clog the microfilter and cause a lean seizure.

 

[Andrewdinsdale]

Congratulations on getting it up and running!

I know it was a frustrating path. But you finally got it there! So great job!

Leaving the Primer bulb in is fine. I use a primer pump. But both work the same way.

Maybe check the vent lines. They could be clogged with debris and causing the tank to pressurize and send fuel to the carbs and cause the N&S to pop off. Thereby flooding the engine.

...and PLEASE PLEASE PRETTY PLEASE. Change those grey Tempo lines out ! You'll be doing a motor rebuild if those lines aren't changed out. So all of that work you just did will be for nothing as the fuel lines breakdown internally and clog the microfilter and cause a lean seizure.

Thanks for a quick detailed reply!

I'll order some new fuel lines now. 1/4 (6mm) lines is that right? Any idea on how much length I need to do the lot? 5 meter roll should do it.

Hopefully if the return line is my issue new lines will solve this. If its not maybe its one of my other lines.

-I am going to do a trailer test at the slip tomorrow morning as I'm thinking a blast on the trailer might help it out.

 

[Cliff787]

No problem, My Friend!

I'll offer any help I can give!

1/4" (6mm) fuel lines; need 25' to be sure(it's less than that at about 21'). But you don't want to come up short and have to run out and get more. Waste of time!

I don't replace my vent lines as no fuel goes through them. So maybe check the one way valve under the bond line (under the blue rubber bumper).

Don't forget the clamps! Count how many you'll need. It's about 21 clamps needed for fuel lines. I normally buy a pack of 25 Oetiker (size is 13.3-13.9mm) pinch clamps.

 

[Mickirig1]

After all that did you check the pop off? That is the point the carb starts pulling fuel. Did you clean the carb really well? They get aluminum salts in them, like fine white sand. Clogs the little low speed ports / holes in carb throat. The little low speed check valve is important. It is on opposite side of fuel pump side. It get any sand under it the fuel can load up that section. When it acts up try opening gas cap or pulling chock nob out a little. All the gray tempo lines need replaced. Use all stainless clamps. Cable tie all the lines in the same route they came from. The front fuel filter can cause problems, the gasket fails. The fuel selector's O ring can fail too. Having a pop off tester I could out which one leaked. It is easier to suck air the fuel. Higher speeds air wins!

 

[mikidymac]

Also get rid of the primer bulb. They can restrict flow and are not needed.

In addition to pop off you also need to check each carb for leak down after you put the diaphragms back in and cover on.

 

[daget24]

Yeah man, replace those old fuel lines and clean out the filters in your carbs. The ethanol in today's gasoline eats the lines up, and then the debris created from the lines gets caught in the filters in the carbs, super lame. You should replace your fuel selector while you're at it.

 

[Andrewdinsdale]

No problem, My Friend!

I'll offer any help I can give!

1/4" (6mm) fuel lines; need 25' to be sure(it's less than that at about 21'). But you don't want to come up short and have to run out and get more. Waste of time!

I don't replace my vent lines as no fuel goes through them. So maybe check the one way valve under the bond line (under the blue rubber bumper).

Don't forget the clamps! Count how many you'll need. It's about 21 clamps needed for fuel lines. I normally buy a pack of 25 Oetiker (size is 13.3-13.9mm) pinch clamps.

Thanks again.

I've now got enough fuel line and oetiker clamps to do the lot just finding some free time now.

I did take the ski to the ramp today and dip it in the water to give it a trailer test- after warming it up it seemed to run great sitting at idle, then I held it at roughly 3000rpm for a minute and it didn't miss a beat, then I let it back to idle and gave it a WOT blast, achieved 7200rpm at WOT for roughly 3seconds but quickly let off as I'm yet to change the lines etc. This is a little higher then I thought the stock 6900 +/- 50 figure was but I presume this is because its not under full load being on the trailer plus cavitation etc.

Anyway I'll get on and change the fuel lines over the next few days.

I'll let you know how I get on.

 

[Andrewdinsdale]

Okay I didn't know primer bulbs could restrict flow, thanks for that I'll probably ditch it now. I'm replacing my lines over the next few days. Cheers

 

[Andrewdinsdale]

Yeah man, replace those old fuel lines and clean out the filters in your carbs. The ethanol in today's gasoline eats the lines up, and then the debris created from the lines gets caught in the filters in the carbs, super lame. You should replace your fuel selector while you're at it.

Okay thanks dude, yes I've got the lines and clamps now so I'll do that in the next few days, my local Seadoo dealer has been a dealer for 22 years and said he knew nothing about the lines but probably because here in the UK theres a lot less of them to go wrong.

I put new carb filters in a couple days ago so probably not going to open the carbs up again.

Why should I replace the fuel selector? Cheers

 

[Cliff787]

The fuel selector valve gets replaced or cleaned out due to the fuel that passes through it.

Fuel additives & contaminants tend to build up and clog the passageways of the selector valve and restrict fuel flow. Fuel knobs when turned can get sticky, have a layer of crust or get stuck in place and people will just tend to just replace them altogether. They only cost $20-$25 USD. So to replace a 20+yr. old valve at the cost of $1.00 per year to operate is pretty inexpensive without any problems.

I recently replaced mine on my '96 GSX after inspecting my valve and it was squeaky clean inside the passageways after 21 yrs. of it being in service. But I replaced it anyways at the cost of $20.00.

 

[Mickirig1]

As old as the ski is, gaskets fail and dry out. The under front hatch fuel filter gasket is known to fail. The fuel selector O ring fails and the fuel system vents fail, after so many years. It takes some maintenance to keep them running right. We know, been ,there found it out !

 

[omboli]

I would check the fuel tank vent line make sure the valve is working

 

[Mickirig1]

Check the vents and fuel lines with a pop off tester. You can make your own and power it with a bicycle pump. Repair manual has the test out procedure for the fuel system and vents. Two piece oil tanks can leak vacuum / air. Easier to suck air then fuel. Get to high draw high RPM you really start to suck air. Older ski's just need some TLC to get back to glory!