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ok I'm ready to give up..

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Ok I'll give that a shot. If I were just testing the pump/carb themselves couldn't I just run the line to a jar of pre-mix?
 
And by hand pump are you just referring to temporarily spicing some sort of siphon pump in line or is there an acutaul pump made for this?
 
scotty6336 said:
One more question though....If there was a crack in my fuel tank would that somehow prevent fuel from being drawn through the lines?
Click to expand...

A quick test I would suggest is to disconnect the fuel line from the fuel pump barb and blow backwards into the tube to see if air bubbles rise from the fuel pickup submerged in fuel inside the tank. Alternatively, you could attach an extension to this fuel line tube and attempt to siphon fuel from the tank into a gas can sitting on the ground.

This second method is the process I use to empty fuel tanks during winterization, but I use a temporary electric fuel pump clipped to the battery terminals to expedite the process. On my personal boats, I install a fuel-proof "T" fitting a few inches before the fuel pump specifically for this purpose, and cap it off when finished. Also, one of those fuel primer bulbs for outboard boats sold in the boating section of most WAL-MART stores can be used to get the siphon action going instead of using an electric fuel pump, it's always nice to have one of these siphon setups around for moving fuel from tank to can or vice-versa, and taking fuel samples from the fuel lines into a clear jar to look for water contamination.
 
Two strokes need oil??? Lol. I guess it is better to have too much than not enough


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if this hasnt been said yet then try it, if youve tried it then lmk, if your fuel tank and lines are not holding air pressure thats one problem, theres a leak some where that needs to be found and fixed, second i would bypass the fuel selector, the way i do it is i unplug the reserve line from the fuel selector and plug it straight to the fuel filter, you will have to take a fuel line off the fuel filter to do so, use that fuel line to plug the reserve lines spot on the selector.. then add pressure to the fuel system via return line that goes to the carbs, check to see if fuel comes out the main line that feeds the carbs, it 'should' flow out freely, if it does, hook it up to the carb, add more pressure via return line, hook up return line and pour a tad bit of mixed fuel in each carb, if your carbs are working properly the ski should run... do all that and get back to us on your results
 
Ok....so I just read all these posts, and today I pulled my tank (again) when I got home from work...I also pulled the fuel selector knob as I also replaced this, along will all lines besides the 2 that go to/from the carbs. Then I took a jug of pre-mix and ran the fuel-in-line to the tank and turned it over for about 20 seconds...and nothing. (I also tried the return line in the tank just to make sure I wasn't losing my mind)

When I was done with this, NO fuel at all even leaked out of the line, or in other words I'd pull the line out of my make shift gas tank and nothing would drip out.

So all this being said, it would seem as though my pump would be bad. But that still makes no sense as the pump worked perfectly fine 6 weeks ago before I replaced the line.

So...I must have something hooked up wrong at the carbs right??? I'm completely lost at this point.
 
scotty6336 said:
Well, on the air line trick, I tried that. Turned on my compressor and after running the air into the return line, with the line pinched as to not flow too much pressure, the fuel line would barely dripple any gas at all, and eventuall wouldn't flow any. It was at that point that I thought maybe it needed more psi, and then the screw-on fuel filter thingy blew off with a loud pop.
Click to expand...

if everything is hooked up correctly, and the fuel filter bowl popped off of the housing when adding compressed air to the return line, I'm betting you have at least two problems:

1. The output side of the (damaged) fuel filter housing is clogged.
2. The pressure relief valve is not working correctly. It should have opened long before the fuel filter bowl popped. You'll want to fix this - it's a safety issue that can lead to an explosion.

Here's a diagram.

25.jpg


I'd recommend pulling everything back out and starting over since you have multiple issues.

During assembly, check the following:
- Vent assembly:
-verify the check valve, you should be able to blow air into the tank, but not the other direction.
-make sure the pressure relief valve opens at the correct pressure.
- blow air through the return line. This will verify that the baffle is not clogged.
- blow air through the "carb in' line with the fuel selector in all three positions. Make sure you feel air in the correct spot on the baffle for on and reserve. Air should not pass with the selector in the off position, if it does, you need a new one. As others have said, not a bad idea to replace it anyway. This test will also verify that the reserve and "on" tubes in the baffle are clear.

A point of reference: the feed and return lines have straight-through fittings. These are in place because the top and bottom halves of the boat were built on different assembly lines at the factory and joined together later down the line... no need to retain these.

Once your fuel system is in tip-top shape, and you know your boat won't blow up, then verify pump/carb operation by running a temporary line from the "in" nipple on the front carb, and the "Y" fitting that normally connects to the return line on the rear carb to a fuel jug. If the pump is good, you'll see fuel rise immediately. This is just quick test to isolate the pump operation from the rest of the fuel system.

BTW - just blow through the tubes with your mouth (i know that sounds bad) don't use a compressor.

good luck!
 

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I think he's saying he pulled the fuel tank out but while he had it out he also tried connecting a jar of premix to the fuel pump to see if the fuel pump would draw fuel from the jar, and it didn't.

Thus it appears his fuel pump isn't working, for whatever reason.

Scotty, BTW, both the fuel line and return should be dropped into the jar, b/c the extra fuel that's not used by the carbs will return back out that line and drip into your bilge. The fuel pump pumps more fuel than the ski uses, the excess is returned to the fuel tank through the return line.

But, it appears you may have a problem with your fuel pump. There are several ways to test it, you've tried one and it failed to pump. Another test you could try is to duplicate the pulse signal that ordinarily comes from the crankcase by connecting a piece of hose to the fuel pump pulse port and place a few psi of pressure on it and see if it holds or leaks, to test the integrity of the fuel pump diaphragm. Not too much pressure, the diaphragm could rupture.

If this test passes, then grab your jar of fuel and connect it to the fuel pump inlet as you tried before. Now using your mouth, alternately force air into and withdraw air from the pulse port using the tubing from the previous test. This will actuate the diaphragm just as pulses from the crankcase would, but without cranking the motor over.

The fuel pump should begin pumping fuel, up from the jar and out the return line. The engine will not be running so the carbs (if they aren't leaking) should not drip fuel, just some fuel will come out the return line, so run that tube back to your jar and watch as you pulsate the fuel pump it will pump fuel.

If the fuel pump will not do this and the diaphragm leak test passes, then one of the two check valves inside of the fuel pump is not working properly.

Give it a try if you like, I've attached a sheet describing how to replace the two check valves and some detail on what to look for, and a link explaining how to test various aspects of your carburetor(s), including the fuel pump test.

http://www.seadoosource.com/mikunitests.html
 

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[MENTION=65307]Sportster-2001-951C-Stock[/MENTION] - Funny! I actually didn't see scotty's last post, I opened the reply window before he posted. Agreed, sounds like there is a pump problem, but I'd still say there's a problem elsewhere in the fuel system as outlined in my previous post.
[MENTION=67594]scotty6336[/MENTION] - can you post some pictures?
 
I really appreciate all the help here. I just ran to my shop to get some plastic adhesive so I can clean this tank and get the repair set up, then on to the fuel issue. I've got all day here and I'll post pics as I go.
 
Hope these show what I have going on....I know the tank looks like crap, I'm going to clean all that old glue that expanded all over off and re-do it.

Tough to see in the pics, but does it look like I have the carb lines ran correctly?
 

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I removed everything except the carbs and the main in/out fuel lines. When I crank it, the return line will blow air bubbles, however the pickup line is not sucking any fuel...at all.

So that tells me the pump has to be working right? Seeing as its blowing air out, so maybe I have something routed incorrectly with the carbs?
 
I think your pulse line isn't hooked up correctly. On a 717, it's right below the pulse nipple on the mag carb, looks like yours is going to the other side of the motor. I've got this same ski in my garage right now, just did the carbs, let me grab a photo...
 
Here you go... same ski as yours.


36.jpg

37.jpg



38.jpg


Adjust your line routing to match these... try the jar test again and report back.

And don't give me any crap about how dirty everything is, I just got this old girl running last weekend. :)
 
falklandsx said:
And BTW - you can get a brand new tank from the dealer for free. :) Check this thread out:

http://www.seadooforum.com/showthread.php?59390-Fuel-Tank-Recall-Question
Click to expand...


Yeah I called my local dealer and they blew me off, but I'll try again. Thanks for taking the time to post those pics, I had it correct but it was great reference.

I just got it running, after pulling the carbs, all lines and tank again I found that I f'd up while building the pto carb. I could blow air through the main carb when not hooked up to the pto, but the pto was blocked up somewhere, and I had missed a diaphragm in there, which luckily I had.

So after putting the carbs back in and running the lines to a make shift gas tank, it did pull fuel, but only if I raised my make shift tank up high where as gravity would help..So IDK if that means I have a weak pump, or if it simply means I need to reinstall everything and use a hand pump to prime the whole system?

But its looking good aside from a crazy run away idle. I'm done for the day now but I'll be back on it tomorrow. thanks for all the help guys
 
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