Pressure testing fuel system 95 XP

[burtshaver2021]

Good day everyone, I’m looking for some advice on how to pressurize the fuel system on a 95 XP, i took a look at the manual and it says to have the fuel selector in the off position, to block the vent line coming out under the rub rail I believe and pressurize to 5 pounds through the inlet line that has the pressure relief valve, then to change selector to on and reserve and repeat procedure. Am I missing anything? I haven’t really had a good look at it, the machine apparently bogs at high rpm but has good compression so I was going to check the fuel system for leaks as I can smell fuel, take the carbs apart and check for genuine Mikuni parts, check the pop off and check for leaks, see how it runs then and procédé from there. Thank you in advance for any and all replies

 

[burtshaver2021]

@etemplet i know you pressure test your fuel systems,

 

[etemplet]

I'm arguing with a 2003 GTI right now. I tell it everything is OK but it says no. For the fuel system check.....What I do is clamp the fuel lines a few inches away from the fuel baffle. I clamp both, ON and RES and put the pump on the inlet line to the carbs. That way I get the whole system. Main things I concern myself with is the water separator and the fuel valve. I pull a vacuum first. I do this because that is what the fuel pump is doing. If I can't pull and hold 5 or so pounds vacuum there is a problem.

Next I pressure test. I take a clamp off one of the hoses RES or ON and I pressure up the system. This is how I test the fuel valve and connections to the fuel valve for leaks. So I take the clamp "off" the RES line (for instance) and I set the fuel selector for ON. I pressure up and it holds proving the fuel selector is not leaking in the on position. I move the fuel selector to the OFF position... it still holds, then to the RES position where it drops to ZERO. Then I do the opposite line. Clamp the RES and remove the clamp for the ON hose/line. Pressure up with the fuel selector on RES. Move to Off and then to ON where the pressure drops. You can play with it. I've gone to 10psi with no issues. I don't know if this is gonna help you more than the directions. Ha ha.

Sometimes I take my fuel pump I use to drain tanks and I hook it up to feed line to the carb. I turn on the pump and pull fuel through the system. I figure if I can move that much fuel through the system steadily I shouldn't have a problem. That said... the GTI doesn't agree. Perhaps it is electrical..... Good luck with yours !!!

 

[burtshaver2021]

Good luck with the GTI, I will play around with it and see what I come up with, No sense of me asking any more questions till I at least try. I would think as long as I don’t go over 5 psi I shouldn’t damage anything so won’t matter to much that I don’t know what I’m doing. Thank you for taking the time to reply, I so appreciate it.

 

[etemplet]

5-8 psi for me. These skis are cunning adversaries but they don't lie.

 

[Goofski]

Good luck with the GTI, I will play around with it and see what I come up with, No sense of me asking any more questions till I at least try. I would think as long as I don’t go over 5 psi I shouldn’t damage anything so won’t matter to much that I don’t know what I’m doing. Thank you for taking the time to reply, I so appreciate it.

Have you had any luck ? My 95xp is doing the SAME. It ran fine 2 days and then the 3rd it Boggs at high rpm’s. Let me know what you find out please. I just got it 3 weeks and have yet actually rode it.. so much for a “water ready ski”

 

[burtshaver2021]

I haven’t had a chance to look at this one yet, I just want to do some testing instead of just replacing everything. If I were you with the bogging I would start by rebuilding the carbs with genuine Mikuni parts, very important to use the Mikuni parts, aftermarket is just a waste of money. At the very least take carbs off, check the pop off pressure, check that the metering diagram is Mikuni will have a red button if it is, make sure needle and seat isn’t leaking. Check compression, check that the fuel filter/water seperator o ring is in good shape, clean the micro filters in the carb, no gray fuel lines right? I would guess that it’s a carb issue. Follow Mikidymac’s carb rebuild thread to the letter. If all this is good and verified try pulling the red wire off of the voltage regulator while driving, if that fixed your bogging then bad rectifier, or hook a volt meter to the battery and rev te ski to 5000 rpm’s, if the reading is over 15 or under 13.5 I believe then the rectifier/ voltage regulator is bad. Let me know how you make out, good luck,

 

[Goofski]

I haven’t had a chance to look at this one yet, I just want to do some testing instead of just replacing everything. If I were you with the bogging I would start by rebuilding the carbs with genuine Mikuni parts, very important to use the Mikuni parts, aftermarket is just a waste of money. At the very least take carbs off, check the pop off pressure, check that the metering diagram is Mikuni will have a red button if it is, make sure needle and seat isn’t leaking. Check compression, check that the fuel filter/water seperator o ring is in good shape, clean the micro filters in the carb, no gray fuel lines right? I would guess that it’s a carb issue. Follow Mikidymac’s carb rebuild thread to the letter. If all this is good and verified try pulling the red wire off of the voltage regulator while driving, if that fixed your bogging then bad rectifier, or hook a volt meter to the battery and rev te ski to 5000 rpm’s, if the reading is over 15 or under 13.5 I believe then the rectifier/ voltage regulator is bad. Let me know how you make out, good luck,

Will start doing that thank you

 

[burtshaver2021]

So I’m trying this fuel system check right now, first thing I did was put the Mity vac on vacuum and attached it the fuel inlet line right were it goes on the carb. Pumped it to 5 pounds of vacuum with the fuel selector valve set to off. I’m losing my vac in about 1 minute so not good I believe. If I turned the fuel
selector valve to on or reserve I lost pressure immediately. I have since clamped off the on and res. Lines just above the baffle. I will report back after I’ve played a bit more

 

[burtshaver2021]

I tightened the cup on the fuel
Filter, I had it off inspecting the o ring. Now with the fuel
Selector in the off position I can hold 5 pounds of vacuum. Just turned the selector to on and lost maybe a pound instantly but then holds at 4 pounds vacuum, pumped it back to 5 pounds vacuum and it’s holding. Switched the selector to reserve and same thing, instantly lost about a pound but after pumping it to 5 pounds of vacuum it’s holding.

 

[burtshaver2021]

I took the clamps off and just clamped the on fuel hose above the baffle, put the selector to on and lost about a pound in a minute, then put the clamp on the reserve and selector on reserve and again lost about a pound in a minute. So I put clamps on both the on and reserve above the baffle and same, lost about a pound in a minute. So I figured it was the fuel filter leaking, I took it out, took the o ring out of my HX which I had just installed about a week ago and it was too big for the XP, went to put it back in the HX and now to big for it as well. I had gotten it from OSD marine. Oddly the old oring from the XP still fit, it didn’t swell/expand at all.

 

[burtshaver2021]

I had an old selector valve from my HX and I tested it by putting vacuum to the on line and then the res line. I’m thinking I’m going to test the selector valve in theXP the same way by taking the fuel line off at the baffle and attaching the vac there. I’m thinking I’m getting my pressure loss at the fuel filter, I’m going to order some new o-rings if I don’t already have some on t he way from seadoo warehouse and it does also have these clear fuel lines which I don’t trust, they don’t fit quite as snug over the fittings as the black 1/4” fuel line. Also thinking of taking the fuel filter off and putting a vacuum cap on the one fitting and the mityvac on the other. Easier for me to test each component individually as I have no luck looking for leaks with soapy water.

 

[etemplet]

Looks like you got it going on. Way to go !! That's how I check it. I did pull a flow of fuel through the system one time using my fuel pump I use to pump out the tanks. If the system can deliver fuel that fast I figure we're good to go. When I connected my pump that way there was a lot of air bubbles flowing through the line
so I replaced the fuel seletor. Good Luck !!

 

[burtshaver2021]

Thank you for the reply, to be clear losing that pound of vacuum over a minute is not good correct? I need it to hold that 5 pounds of vacuum pretty much indefinitely?

 

[burtshaver2021]

I think I found it. Sorry for the long post about come but I’m going to go through what I did this morning and please feel free to correct anything I did wrong. I took the fuel filter off it’s bracket, took the hose off of it going to the OUT on the fuel selector valve, put my finger over the end of the nipple on the filter and put 5 pounds vac on fuel inlet line that goes to carb, HELD PRESSURE, fFILTER GOOD. I then took the lines off the baffle that go to fuel selector and put vac on ON line where it fits on baffle HELD PRESSURE. I then put vac on the RES. line where it attaches to baffle, HELD PRESSURE. I then took the line back off the filter that goes to OUT on selector valve put vac on line where it attaches to filter and LOST PRESSURE. Tried the same on old selector I have to the out on it and it held pressure. Changed the line from fuel filter to OUT on selector, repeated test and now HOLDS PRESSURE. Very simple stuff I know, but find it very gratifying to learn one more small thing about these machines. And as a bonus the o-ring that i took out of my HX now fits again. Just sitting out overnight it must have given off some of the fuel it soaked up and shrink back into shape. I really appreciate the help, makes it much easier when you have someone to ask that knows what they are doing. THANK YOU.