94 SPX Not Picking up Fuel

[jmbmichael]

Alright, I just got a 94 spx and the guy said he was having fuel problems with it but didn't know where to start. I got to looking and fuel is not even making it to the fuel filter. It still has all the original gray hoses so that's where I'll start. Do these actually have fuel pumps on them or is it all pressure based? Other than the hoses what can I check? Thanks

 

[seadooya]

bypass or replace, the inline fuel filter. The o-ring inside the filter part, is bad.

 

[6KJR]

The fuel pump is located in the MAG carb. Probably time for a carb kit if its never been done.. Also check the pulse line coming from the crank to the MAG carb as well. If its bad it wont work the pump.

 

[marlboroa]

not to hijack your thread but im having the same problem with the same year and model of ski. i dumped out the fuel filter and its not filling back up. mine has about half of the grey lines replaced. if you figure it out please post your answer.

 

[marlboroa]

got mine fixed, someone thought it would run better without a o-ring in the screw on filter.

 

[jmbmichael]

I pulled the fuel tank to replace some of the fuel lines and found this under it. Any idea what it is and where it goes?

 

[jmbmichael]

I also checked the filter and it and the o-ring are fine. I went ahead and replace it with a clear inline and its still not getting fuel to the filter. How do I check the pulse line coming from the crank???

 

[seadooya]

Replace the fuel lines. If anything, locate the "res" fitting, on the tank, and run a fuel line, from it, to the carb, while keeping the fuel selector valve on the "off" position. Pulse line is the fuel line from casing to side of front carb.

 

[jmbmichael]

Any ideas as to what the picture is in the above post?

 

[seadooya]

not a clue, bud.

 

[jmbmichael]

not a clue, bud.

I think I just found where it goes. Now, what's it for, where does the hose connect to, and what's it called so I can order a new one.

 

[jmbmichael]

I think it's a vent line for the oil tank. Can anyone confirm that? If that's it, any idea what it's called or a part number?

I got all the fuel lines changed, cleaned the Selector, cleaned fuel tank and I'm still not getting fuel out of that tank. I ran a line to the reserve fitting on the baffle straight to the filter so I could see if it was pulling any fuel and nothing. What would be my next step? Is there anyway to test the pump?

 

[seadooya]

dont run the line to the filter. Run it directly to the carb. If your o-ring is bad, inside the filter, you'll get the conclusion, your having.

 

[jmbmichael]

dont run the line to the filter. Run it directly to the carb. If your o-ring is bad, inside the filter, you'll get the conclusion, your having.

But I've already checked the oring and filter, even used a different inline filter.

 

[djredman99]

I think it's a vent line for the oil tank. Can anyone confirm that?

I believe it is actually the vent for the gas tank. On my machine, the vent line from the baffle comes to a 'T' valve and shoots off to the vent you pointed out as well as another vent right in front of where you sit (covered by the seat when in place).

 

[djredman99]

I got all the fuel lines changed, cleaned the Selector, cleaned fuel tank and I'm still not getting fuel out of that tank. I ran a line to the reserve fitting on the baffle straight to the filter so I could see if it was pulling any fuel and nothing. What would be my next step? Is there anyway to test the pump?

Looks like you should do a pressure test on your fuel system. Refer to the shop manual for this procedure.

If you pass there, you should test the pump on your carb, again, refer to the shop manual. PM me if you need further assistance.

 

[seadoosnipe]

Check valve...

Any ideas as to what the picture is in the above post?

I haven't read through the rest of your thread yet, but since it's so long, I thought I'd reply a little at a time.

The piece your holding up is either your fuel line check valve {#39} or your fuel tank pressure relief valve {#21}, which is set around 1.5 psi. Either way, it needs to be put back on. The check valve protects the tank from getting water in it and the relief valve bleeds off excess pressure build up in the tank. Kinda like when you take off the gas cap of your lawnmower gas can. Now, I'll read on.......:cheers:

 

[seadoosnipe]

No fuel....

O.k... got to read the rest of it.

First, the grey fuel lines? .. Yeah, they caused your problem. There could be a few things wrong right now. You say you can't even get gas to the fuel filter. Are you certain your pulse line is connected and working? Do you have good compression on the engine? You need good compression for the pulse line to work. But, the most common problem with not getting fuel? Either you've put one or more of your lines on wrong, or you've got to prime your fuel system of all air.

I've posted this several times. If you replaced all your fuel lines, then you need to fill the lines with fuel. The pulse line pump will not pump air, only fuel. So, you need to get fuel to the pulse pump inside the Mag carb.

The fuel system actually works by vacuum to run the motor, the pulse line pump only makes sure your carbs have a steay supply of fuel. It runs in a circle from the tank, through the body of the carbs, then back to the tank. There is a restriction orifice built into the carbs to always make sure you have fuel inside the carb and lines.

If your ready to start and you know that everything is connected correctly, take off your airbox and expose the flame arrestor. Take a regular grocery bag (the plastic kind) and put it over the intake of the carbs. This will take all the engines vacuum and pull the fuel through the lines and into your system. You might need help to have someone start/turn over the motor, while you hold the bag over the carb intakes. If you hear the motor hit, quickly remove the bag. Now, try and start the motor. If you hear it hit, you have fuel up to the carbs now. You can't run the motor without the flame arrestor on. It's part of the system that creates manifold pressure (vacuum) that draws fuel into the motor........ I hope this works out for ya!

 

[jmbmichael]

Alright, I checked the baffle and evidentally someone had already messed with them and put them back in the wrong place, I just assumed they were right when I replaced them. So I fixed that and filled the fuel lines with fuel, used the plastic bag trick over the baffle and she started right up. But it only ran the fuel out of the lines and died. It still does not seem to be pulling fuel.

 

[jmbmichael]

I pulled the return line off the carb and pulled the inlet tube off. I blow pretty hard through the return line and just got mostly air out of the inlet with a few squirts of gas. I shouldn't be getting any air through there should I? Any ideas

 

[jmbmichael]

OK, I've got it narrowed down. I attached a line going to the inlet on the fuel filter and ran that to a bottle of fuel and tried to start it and it sucked fuel and started right up. So my problem is somewhere before the fuel filter. I've changed all the fuel lines and made sure they are in the correct places. I haven't really checked the vent lines for the tank. I pulled the line from the baffle and blew through it and air came out of the vent on the top but not the vent on the bottom of the hull. Is that normal or could that be plugged up?

 

[djredman99]

The vent line from the baffle should split in two lines at a 'T'. One of these lines contains a pressure relief valve, which releases over-pressure built up in the system. The other line contains a check release valve which lets air into the system when pressure is low (when you burn gas, more need for air in the system). If this line is not working, fuel will not flow to your carbs. This may be your problem.

You should be able to blow air out of the vent line, as you already did. You should also be able to suck air in through the line as well, which you did not try yet.

 

[jmbmichael]

The vent line from the baffle should split in two lines at a 'T'. One of these lines contains a pressure relief valve, which releases over-pressure built up in the system. The other line contains a check release valve which lets air into the system when pressure is low (when you burn gas, more need for air in the system). If this line is not working, fuel will not flow to your carbs. This may be your problem.

You should be able to blow air out of the vent line, as you already did. You should also be able to suck air in through the line as well, which you did not try yet.

Is there a way to check the "check release valve"

 

[djredman99]

Just try sucking in through the line as opposed to blowing. There should be no fuel in the line as it is a vent line only, but be careful of any fluid that may come out.

Even though I previously said this may be your problem, I am doubtful as once you primed your lines following snipe's advice, I would think you should have been able to pull fuel into the lines for a little while before not having air put back in caused enough of a vacuum to starve your fuel lines. I have never seen this happen first hand, so I don't know how quickly the effect would take place.

If you have the tools available, or don't mind running to an auto-parts store and laying down $40, I still think you should test your fuel systems pressure. You may have a leak in there somewhere.

Just to be sure...You don't have any fuel leaking and laying in the hull do you?

I pulled the return line off the carb and pulled the inlet tube off. I blow pretty hard through the return line and just got mostly air out of the inlet with a few squirts of gas. I shouldn't be getting any air through there should I? Any ideas

If your fuel lines were completely filled with gas, you should expect no air to come out. But, from the sounds of it, they were filled with air.

You could, if you don't have or buy a pressure tester, hold or pinch close the inlet line while blowing in your return line. This will pressurize your system. Listen for air escaping from anywhere along your fuel system and tank. Preferrebly in a quiet environment! Pinch off your vent line so none of your pressurization escapes through the pressure relief or you may be fooled by hearing air escape out there. Also, soapy water will bubble where air leaks, so you could spray your lines and tank down to help. This certainly is not nearly as effective as having a pressure tester, but may help.

Also, I realize you have done this already, but make sure all your connections are correct. I think you said you found one that was messed up, but don't stop there and assume it was the only one.

This is the best advice I can give to you for now. Perhaps Snipe will chime in again with a more expert view on it.

 

[jmbmichael]

I just figured it out. The fuel valve seems to be bad. I took the reserve line off the fuel valve and ran it to the filter and worked prefectly. I took the valve off and blowing through the out port with a compressor it didn't matter where the knob was pointing, air came out both ports even in the off position.