96 XP carb rebuilding question

[Richieskis]

Hello everyone.
OK, I have a set of carbs for my 86 XP that I need to clean and rebuild, they have come off of a 96 XP that sat for 9 years, with gray fuel lines, so I am sure they are a mess. I have the rebuild kits, and read and watched (you tube) as much as I can find on how to do this, My one question is doing a pop off test on the needle and seat, I see you put oil on the needle and seat and pump up the pressure on the pop off tester, I have my tester, just not sure what pressure I am looking for, and am I too match something, like sure booth carbs pop off at the same pressure ? do I do this to match new springs ?

Thanks

 

[SabrToothSqrl]

I've never bothered with a pop off tester. Just replaced all the parts with OEM parts and put them back together. so far, 8 ski's later. works fine.

 

[mikidymac]

I always test pop off and if you already have the tester you might as well. You can only do one carb at a time and your tester will go on the fuel inlet fitting on the carb and you need to plug the return fitting or just put your thumb over it. Hold the needle lever open and squirt a little WD-40 in the needle seat because you will not get an accurate reading with it dry. Place a paper towel over the carb so when the needle does pop you do not get WD-40 in your face. Pump up your tester slowly and watch the gauge climb, it should be steady and it keep climbing until it pops and that is your pop off pressure. It should be a quick, sharp POP and not a slow leak. The pop off pressure for a 1996 XP is 27-39 psi per the manual, I usually set mine at about 32. The important thing is to have both carbs the same. I have not had much luck using the springs that come with the rebuild kits because they always cause the pressure to be too high or too low so I either order new ones from seadoo or just reuse the old ones. Make sure you take a few readings and apply WD-40 each time. When you are done and think you have it and the carb is all the way back together plug the return line again and pump your tester up to about 10 psi and just make sure it holds the pressure for a few minutes. This is very important because if it does not it will slowly flood the engine and be very hard if not impossible to start. If it does leak take the carb back apart and find out why.

 

[Richieskis]

Guys, thanks for the info, i wanted to make sure these carbs are correct, as I have been having a challenge with this ski, and have narrowed it down to carbs or the motor... hoping carbs,

 

[mikidymac]

A little more info and we might be able to help more. How was it running? What color are your fuel lines? Did you find anything in the crabs like plugged filters?

 

[Richieskis]

long story, the seadoo that has the problem, is my 96 XP, last summer, 2012, mid way through the summer, the kids riding it ran it out of oil, so I did a top end, after top end work, the seadoo ran great, after about 20 hours on the new top end, the kids, and I guess with my help lunched with out the drain plug, after we got the water out, and the water was only about 1/3 a the way up from the bottom of the seadoo, but enough to get water in the rear electrical box and maybe the front electrical box and the bottom of the motor, it had a real bad miss fire, so I did some checking and figured it to be a bad rectifier, ran bad with red wire connected, good with out, order new rectifier, replaced, still had same problem, by the way last winter 2012, before last summer, the fuel lines were replaced and carb fuel filters cleaned. I talked to my local seadoo shop he gave me a 2nd rectifier, same thing problem did not go away, he said might be stator, or MCM computer, so I left it with him, in sept 2012, now March 2013, he said he can not fix it, he replaced stator, I have the one that was on it and it has the new one, and said he tried different MCM computers and even re-did spark plug wires, told me come get it I am on my own, he thought that was in the wiring, and I needed to change out the complete wiring system, everything, hood gages, start swith, MCM computer and rear Ignition box, along with all wires, ok, so as luck with have it, CL had 96 XP for $400, the seadoo guy was going to charge me $300 if it was the stator, so I figure what the heck, and it was only 5 miles from me, the seadoo was complete, has been setting for 9 years, seat messed up and dead battery of course, but I was able to crank it to check compressing, it had 160 psi, so I had donor seadoo, he did not have pink slip, but came with garage stand, so I took all the wiring and electronics out of the donor and put in my seadoo, first I changed out rear box and MCM computer box and wiring between both, SAME Problem, I have to say I did not try and disconnect the red wire, but figure that bridge is crossed, so next I changed out the VTS mod, best part of this, the old on on my seadoo did not work, this one does, score, savings for me, but still have same problem, rough running motor, ok, changed out start and VTS switch, guess what same problem, now change out hood and all gages, you guessed it same problem, rough running motor, this time, I even put it back in the water just to make sure I was not hearing the miss fires, ok, so the seadoo now has a complete donor wiring system, only part from the original is the fuel baffle, but that one is working, oil tank sensor, and speed pick up, figure that can not cause rough running motor, so I am going to take the donor seadoo's carbs, rebuild them, as that seadoo still had gray lines and gas setting for 9 years, and try them, wish me luck, if not i have the donor seadoo motor, already pulled out of the donor seadoo, if I need to do motor swap, I am getting real good at working on these things

any thoughts ?

 

[Minnetonka4me]

LOLOL ok so you have replaced everything other than the motor. Heres the problem...its the motor.

Any idea if the guy that did the stator found water in the mag housing?

Regardless...I guarantee with all the stuff you have done its most likely air leak.

 

[mikidymac]

I agree with Minnetonka, you said that the kids ran it out of oil and only did the top end? I would say your crank and crank seals were already on the way out before you did the top end. The crank does not last long without oil and then on top of that they flooded the engine too? I would say at the very least you have an air leak but I would not atempt another season on that bottom end. You might have a good donor engine from the other ski so if I wer you I would pull it and buy a $60 complete gasket kit and take it apart replacing the crank seals and all gaskets, clean the RAVE valves and inspect. If you want to keep the old engine pull it, buy the complete gasket kit and a $275 crank from SBT and reuse your new top end.

You have already done so much work but your "mechanic" should have hit a red flag when he was informed that the ski was run out of oil instead of chasing electrical problems. There is a chance you might have 2 good 1996 XP's with minimal cost. I think both ski's have good electrical systems.

 

[Richieskis]

LOLOL OK so you have replaced everything other than the motor. Heres the problem...its the motor.

Any idea if the guy that did the stator found water in the mag housing?

Regardless...I guarantee with all the stuff you have done its most likely air leak.

Yea, after I change the carbs I will have changed everything but the motor, and yes, I am feeling like it is the motor,
last summer when it ran out of oil, I should say low on oil, the motor only had minor top end damage to one cylinder, put after all this, I am thinking I do have a seal leak on the motor, I have only had a few min. to work on it since it came back from shop, as the seadoo is at our river house and the donor seadoo is at my main home in Calif. is there a way to check to see if it has a leaking seal, like a POP of test ?

The mechanic, did not say he found water, I have the front mag and cover that came off, he gave it to me, it did not look like it was wet, but hard to tell, it has had lots of time setting around after he pulled it

 

[Richieskis]

I agree with Minnetonka, you said that the kids ran it out of oil and only did the top end? I would say your crank and crank seals were already on the way out before you did the top end. The crank does not last long without oil and then on top of that they flooded the engine too? I would say at the very least you have an air leak but I would not atempt another season on that bottom end. You might have a good donor engine from the other ski so if I wer you I would pull it and buy a $60 complete gasket kit and take it apart replacing the crank seals and all gaskets, clean the RAVE valves and inspect. If you want to keep the old engine pull it, buy the complete gasket kit and a $275 crank from SBT and reuse your new top end.

You have already done so much work but your "mechanic" should have hit a red flag when he was informed that the ski was run out of oil instead of chasing electrical problems. There is a chance you might have 2 good 1996 XP's with minimal cost. I think both ski's have good electrical systems.

Funny thing he, the mechanic said, the motor is strong, that I dont need to find a seadoo with a good motor, he said find one with a blown motor just for the electreical parts,

I was planning on checking and cleaning the rave valves, on the donor, but I guess, if I get to the point to put it in new seals would be good insurance.

Not sure if I want two 96 XPs, I think one is enough. I will have alot of spare parts to keep this one running ....

 

[Minnetonka4me]

Yeah I went thru this on a customers 94 XP. He brought to the dealer to get ass raped on a top end job and when it didnt run right they wouldnt do anything for him.

I changed EVERYthing...some things twice. Ended up taking it on trade for a 97GTX. Took apart the motor and the whole thing was pretty much junk including a shotty top end job.

The reason I asked about the stator is b/c when it is run with water in the housing a layer of rust will build up on the crank and tear apart the crank seal. Sounds like that wasnt an issue here though. It would be VERY apparent on the old stator.

 

[mikidymac]

Well, I am not sure how he could have determined that you have a "strong" motor without pulling it out and doing a leakdown test. I don't know the guy but sounds like he thought throwing money at it was the best fix. I could be wrong though. He could have checked compression but that is only half the story. If the engine has never been apart then you almost definatly have a seal leaking. Usually it is the rear crank seal or the rotary cover. The rubber parts get hard with time and just don't seal. The only way to be sure is to block off the intake and exhaust ports and pressure test the engine to 8 psi and watch the gauge. If it drops start spraying the entire engine with soap and water and find the bubbles. Somebody here was making some trick aluminum blockoff plates for $65 if I remember correctly.

BTW: you should ALWAYS do a leakdown test on any engine that has been apart.

 

[73Diesel]

If the motor runs and you dont want to pull it to do the leak down test. You can always use carb cleaner or equivelant. I use 2+2. All you have to do is start the motor and spray a little at the end seals. If the RPM's pick up then thats the seal thats bad. Its and old snowmobile trick to see if the PTO seal is bad. Just my 2 cents.

 

[mikidymac]

If you decide to try 73Diesel's trick make sure to spray the carb bases, intake manifold/rotary corver and base gasket areas too. I prefer brake cleaner as carb cleaner can take off paint and damage plastic.

 

[Richieskis]

If you decide to try 73Diesel's trick make sure to spray the carb bases, intake manifold/rotary corver and base gasket areas too. I prefer brake cleaner as carb cleaner can take off paint and damage plastic.

I may give this a try after I change out the carbs, and if I still have the problem, as I still have hope it is the carbs, as it is alot more work to R & R the motor. then to R & R the carbs, and summer is right around the corner and I have to work on this seadoo at my river house. and I have to get a boat ready also,

Rich