1994 XP Carb Rebuilt - Flooding

[TrailD]

I rebuilt the carbs for my 94 SeaDoo XP. Unfortunately used Titan Rebuild kit because it showed new needles and seats with it. Installed and seamed to run good at first but when shut off and try to restart it was flooded. Pulled apart and ran pop off pressure test and was failing to hold pressure after first pop. Note I reused the spring, lever arm and pin from original.

I went ahead and bought new SeaDoo OEM needles and seats and ran pop off pressure test and have both popping at 19 to 20 psi and holding15 psi. Installed and ran erratic. Appears to be flooding out Mag side for sure. Could see fuel droplets in carb throttle body at idle. Also removed plugs and see vapor when cranking.

Removed and checked pop off pressure test again and all good. I decided to try pop off test again with diaphragms installed and wouldn't hold pressure at all. Took diaphragm back off the mag side and tried again and this time the pto side would pop off at 15psi but do like three pops quickly finally closing and hold 5 psi.

I know my first mistake was not buying OEM Mikuni kit but looking at diaphragms don't see what could really be different. With that said could I just by the Diaphragms?

 

[burtshaver2021]

I would say just buy the back to OEM kit from OSD but if you want to try and see if you can save some money you will need new diaphragms at least. Good that you’re using the original spring but that pop off seems pretty low. I’m seeing 19 to 35 on seadoo source and from my limited experience they perform better near the higher end of that spectrum. Pretty sure the spring for they engine has been discontinued

 

[TrailD]

@burtshaver2021 Manual says pop off should be 16 to 21 psi for XP 22 to 29 psi for all other models. So I am at higher end of range.

After playing with it I got the pop off to hold / work with the diaphragms installed. I put back on and ran and would run idle for about 30 seconds then die. Tried again and when pumped throttle was bogged down. let idle for about 10 more seconds and died. Would not restart without removing plugs and cranking fuel out. Flooding again.

Pulled carb and ran pop off test again and now the PTO side would bleed through air at about 20 psi but never pop off. Can anyone explain this?

 

[burtshaver2021]

Sea Doo PWC Carburetor Reference
I’m seeing 19 to 35 on Seadoo source. Seems weird but I never trust or use the manual for pop off specs.

 

[burtshaver2021]

Are you still using the diaphragm from the Titan kit? I believe it was?

 

[mikidymac]

You can't use any aftermarket carb parts, period!.
Genuine Mikuni parts or nothing, you will just be chasing your tail and we can't help you.

1994 XP has the dual carb 657X engine. You should be running 80 gram springs and 1.5 needle and seat. Pop off should be clean at 38 psi.

 

[TrailD]

Are you still using the diaphragm from the Titan kit? I believe it was?

Yes but have ordered Mikuni Kit

 

[TrailD]

You can't use any aftermarket carb parts, period!.
Genuine Mikuni parts or nothing, you will just be chasing your tail and we can't help you.

1994 XP has the dual carb 657X engine. You should be running 80 gram springs and 1.5 needle and seat. Pop off should be clean at 38 psi.

New Mikuni Kit on the way. I am using original springs, arm and pin (not any supplied in Titan kit) and have Genuine 1.5 Mikuni Needle and Seats. ? 38 psi as way higher than any specs seen.

 

[mikidymac]

If the stock spring is an 80 gram and I am pretty sure it is and a 1.5 needle and seat it will yield 38 psi.

 

[burtshaver2021]

What I’m seeing is that the stock spring was part number 270500242 which was a special spring and is no longer available, pop off with that special spring is listed in Seadoo source as 19-35 with a 1.5 needle and seat. Thai is for a 94 XP with the 657x with dual carb. That lists 132.5 main jet and 75 pilot jet.

 

[mikidymac]

Correct, I made my own spring list years ago and bought a 242 to compare. It is closer to a 80 gram than a 65 gram and is all that is available now. If you have the original spring then I would expect it to be between the 35 and 38 psi from the mikuni chart.

1994	SPX	270500130	730-03027-T	95 gm
1994	SPI	270500130	730-03027-T	95 gm
1994	XP	657x	270500242	730-03033	80 gm
1994	XPI	270500130	730-03027-T	95 gm
1994	GTS	270500130	730-03027-T	95 gm
1994	GTX	270500130	730-03027-T	95 gm
1995	GTS	580	270500130	730-03027-T	95 gm
1995	GTX	657x	270500242	730-03033	65 gm
1995	HX	720	2	270500267	270500267	80 gm
1995	SP	580	1	270500130	730-03027-T	95 gm
1995	SPX	657	270500264	730-03033	discontinued try 65 gm
1995	SPI	580	1	270500130	730-03027-T	95 gm
1995	XP	720	2	270500267	730-03033	80 gm
1995	XP800	787	2	270500267	730-03033	80 gm
1996	XP	787	2	270500267	730-03033	80 gm
1996	HX	720	2	270500267	730-03033	80 gm
1996	SP	580	1	270500130	730-03027-T	95 gm
1996	SPX	720	2	270500267	730-03033	80 gm