XP with fuel issues

[Scottacampagna]

Hello,
Thank you for this site and the information that is available on it.
This is my first post on your site, if I am posting it in the wrong department I apologize.

I recently purchased a pair of 97 sea doos, the GSX runs great however the XP seems to starve itself for fuel at times. I have rebuilt the carbs and changed the rectifier (it was bad) thought the problem was solved, took them out today and although it's better it still cuts out and doesn't wanna run. It will run along for a half hour just fine, then gets sluggish and won't do more than a 1/4 throttle. Shut it off and restart it and she goes for a couple hundred feet then does it again. Or sometimes it will starve itself and clear itself out on its own. It still has the original grey fuel line, could that be a problem? Any suggestions are greatly appreciated.

 

[Sportster-2001-951C-Stock]

This is an easy one but first I must point out the obvious: The grey fuel line is rotted internally and will eventually plug your carbs small filters, some of this will actually pass through and plug the small passages in the low speed fuel circuit.

For the current running issue, you have two check valves in the fuel tank venting system, the one that allows makeup air to enter the fuel tank is gummed up. The other check valve limits the maximum positive pressure from fuel vapors. The problem is, your fuel tank is developing a vacuum pressure internally as the engine runs and consumes fuel from the tank no makeup air is entering as the fuel is being consumed. A quick test is to crack the cap open, this allows the vacuum to escape and result in an immediate improvement.

Congrats on a successful carb overhaul.

 

[Coastiejoe]

Moved to the 2-stroke forum,,,

 

[Scottacampagna]

This is an easy one but first I must point out the obvious: The grey fuel line is rotted internally and will eventually plug your carbs small filters, some of this will actually pass through and plug the small passages in the low speed fuel circuit.

For the current running issue, you have two check valves in the fuel tank venting system, the one that allows makeup air to enter the fuel tank is gummed up. The other check valve limits the maximum positive pressure from fuel vapors. The problem is, your fuel tank is developing a vacuum pressure internally as the engine runs and consumes fuel from the tank no makeup air is entering as the fuel is being consumed. A quick test is to crack the cap open, this allows the vacuum to escape and result in an immediate improvement.

Congrats on a successful carb overhaul.

Thank you for the reply, I tried opening the cap to see if that solved the problem but no luck. Could it be the reserve selector? I am also wondering if the fuel pump could be bad? Thanks again!!!!

 

[Sportster-2001-951C-Stock]

Absolutely, the fuel selector valve may be plugged with trash and in that case you can bypass it if you want to test the theory. Most guys buy a new one in case of these problems, and some really cheap ones have not worked well.

 

[Mickirig1]

Keep reading up on carbs and fuel systems in past postings. There is days of reading on it. I would go with a possible air leak in your system. Clogged filter or pickup.

 

[Scottacampagna]

Keep reading up on carbs and fuel systems in past postings. There is days of reading on it. I would go with a possible air leak in your system. Clogged filter or pickup.

I ordered new fuel line, a new selector switch and an inline filter. Gonna see where this takes me. I really appreciate the response!!

 

[Strizzo]

Absolutely, the fuel selector valve may be plugged with trash and in that case you can bypass it if you want to test the theory. Most guys buy a new one in case of these problems, and some really cheap ones have not worked well.

i had the fuel selector on my 97 xp start sucking air also. its a hard pill to swallow replacing on the later skis since they're not so cheap like the 1/4" ones.

first step is you need to replace all the grey fuel lines, while you're doing that you can replace the fuel selector as well.

 

[mikidymac]

for the 5/16" fuel valves take a look at the WSM ones as they are cheaper than the OEM ones and appear to be good quality. I know HFGreg sells them.

 

[Scottacampagna]

Well, I replaced all fuel lines, the selector and added an inline fuel filter. While I had the carbs off I pulled the small filters out and ckeckers/cleaned them as well as changed the plugs. Took it to the lake today and ran great for a bit then started hesitating again. Could it possibly be the stater? I am not sure where else to look for the problem. Although it's has every symptom of a fuel issue I don't know if it may be electrical or not??????
Thanks for any help.
Also, is there a fuel pump in the tank? And could that be going out? Thanks

 

[Coastiejoe]

How long ago did you redo the carbs as compared to when you replaced the lines?

Unplug the rectifier the next time it happens. You could have gotten a bad one and or the stator may be bad and or be partially shorted due to how it is assembled.

 

[Sportster-2001-951C-Stock]

I'm wondering now, assuming the symptoms remain the same, if the engine is getting too hot. The reason is, if a 2-stroke is overheating they will lose power.

Check the lower block drain isn't clogged with sand, a good amount of cooling water exits from the block drain while running and if this drain is clogged the engine will run hotter than normal and still might not trip the overheat sensor.

In this case running at low speed I think will allow the engine to cool off but then as engine speed increases it begins to heat up and power is lost.

Just another idea of something to look for.

 

[Scottacampagna]

How long ago did you redo the carbs as compared to when you replaced the lines?

Unplug the rectifier the next time it happens. You could have gotten a bad one and or the stator may be bad and or be partially shorted due to how it is assembled.

The carbs were just redone. They don't even have 4 hour runtime on them.
I really believed it's was a fuel related issue I was having. But now I'm not sure and have been thinking that the stator could be the issue. Will the stator come in and out? Like I said its very intermittent.
Thank you

 

[Coastiejoe]

It can. Depending on heat and if there is something broken floating around in there.


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[Scottacampagna]

I honestly don't think that it's getting hot, but I am willing to look at all aspects of this. It's getting frustrated because I am sure it's something simple. I just can't put my finger on it. I am going to add this to my list of possibliltys. Thank you again for the info.

 

[Scottacampagna]

Do you mean something on the stator may have come apart?

 

[Sportster-2001-951C-Stock]

The regulator rectifiers tend to develop lose connections internally, and/or it's possible something might be worng with the stator. Eliminate the possibility by temporarily disconnecting the regulator and see if the problem disappears. While disconnected, the charging system will be disabled.

 

[Scottacampagna]

I just got home from a buddies house where we unplugged the rectifier and it ran great. He thinks it could be in the stator and recommends changing both the stator and rectifier out. I have a GSX that runs great and I'm wondering if I should pull the rectifier out of that one and see if the problem is solved.
Thought?

 

[Sportster-2001-951C-Stock]

I'd swap the rectifier first probably but considering you already had a bad one and now it's bad again I'm wondering if the stator is causing them to fail AND the rectifier fuse is too large? If the stator is shorting intermittently AND the fuse is too large, the rectifier is in jeopardy.

So if you only swap rectifiers then put the next lower size fuse in (10Amp ?), to provide more conservative protection the rectifier.

Or maybe the rectifier you bought just can't handle the power (cheapo aftermarket ones often can't).

 

[Scottacampagna]

That's kind of what I was thinking, swapping the rectifier first but if it's the stator I am probably gonna lose the 3rd rectifier. So I have an OEM stator and rectifier that I am going to install this week and hope for a fix.
I am pretty sure the 2nd rectifier I got was OEM as well

 

[Scottacampagna]

It's fixed!!!! Swapped out the stator, rectifier and swapped out the fuel tank (it was recalled) took it out to the lake yesterday and burned a tank of fuel without any issues. Thanks for all of the help with this.

 

[Barnsnelbon]

Have you checked the fuel filter? Mine has gunk in the bottem of the gas tank that keeps clogi g up the fuel filter