97 Seadoo XP Carb Adjustments & Tune

[seadooxp89]

I have a 97 Seadoo XP . Engine brand new rebuilt. Rebuilt the carbs and had a problem with popoff pressure had to order original springs and fix that problem which I did. Now when I start the ski on the water right after Idle on the throttle the ski bogges out and wants to die and shut off but then if I give it a little more throttle it goes. I let the ski warm up and tryed at the same spot again a little bit over idle and it bogged down and wanted to stall out again. I tryed it several times and everytime it wanted to do the same thing bogged down and start to stall out. Might be a hesitation but I get nervous and give it a little more throttle and then it goes so I'm not sure. Would this be the ski running too lean or too rich? I have a feeling its the low speed screws but dont know if I should enrich the fuel or lean it out by turning the low speeed screw in or out. The Low speed are at 1 and 1/4 turned out because alot of people said to turn them out 1 1/2 but the book says 1 so I went in between. When the popoff pressure was too low it never did this and had no hesitation or bogged down at all but it was dumping extra fuel into the cylinders. Can someone help me ? Which way should I turn the low speed screws or is that not the problem?

Sorry I'm a beginner with jetski's and trying to learn. Thanks

 

[seadooxp89]

Can anyone help me with this?

 

[hotrodssnova]

Have you checked out the sticky about carb tuning?

 

[Strizzo]

if you have your low speed needles set to spec, it sounds like your accelerator pump may not be squirting like its supposed to.

 

[seadooxp89]

How can I check the accelerator pump ?

 

[seadooxp89]

How do you check the accelerator pump? Also when the pop off pressure was too low and it was running rich it did not have this issue but after the first time on the water it wouldn't start in the water but now after I put original springs back in and pop off pressure is right now this issue exists. Can someone help me?

 

[96spxpos]

Have you adjusted your idle? not saying its the root of your issue, but it most definitely contributes. That ski has a tach I believe, correct? What is it set at? it should generally be set at around 3k out of water and 1500 in water...so if its at like 900 or 1,000 in water, that's a big gap from idle/low speed jet.
also, here's the sticky in case you haven't looked at it
http://www.seadooforum.com/showthread.php?40380-Carburetor-Adjustments

 

[seadooxp89]

The ski does not have a tach stock. I bought a inductive tach and adjusted the idle to around 3k out of the water it stays right around 3k idling out of the water. I haven't check the idle rpms when is in the water because I didn't have the tach to check it when I brought it to the water. Would the idle being set too low give it that hesitation right after idle when you give it a little throttle and it sounds like it is dying out and then you give it a little more throttle and it takes off. Then I come back off the throttle to where it wanted to stall out and it does the same thing it sounds like it wants to stall out like its not getting enough fuel or air or something. Would the idle setting do this?

 

[96spxpos]

Hey bro, there are a few carb experts on here, and I'm having carb issues myself that through major trial and error, I finally got my issue worked out. So, through deduction and trying things, I'm not saying that this is the right fix or cause, but on my 96 spx, the idle was too low, and the ski had a dead spot from it, where it took a second or two to respond when I'd nail the gas, then id have to constantly give a little gas when I let off the throttle, and when I idled or it would die. it sounded ok out of the water (no tach), but was entirely too low in the water. I raised the idle in a quarter turn increment, found the sweet spot, and issue was pretty much resolved.

It's worth a shot until someone else chimes in.

 

[donkey]

sure sounds like the transfer ports are plugged,if u have sbns,(accelerator pumps),there will be 2 little holes,bns (no accel pumps)have 3 transfer ports,,they supply fuel at small throttle openings,,,if u look in the carbs(off the ski,in from the base of carb)just before the throttle blades u will see these holes,,they r tiny,,blow them out with carb spray till u see them flow.if they were plugged,,u will see a big difference while u are spraying. take a look,,it might be yor prob,,might not,,but its free to check.

 

[Mickirig1]

Did you pull the jets out when you clean carbs ? ALL the parts are replaced? Check valves installed correct sides and back flow pieces? All low speed turned out to spec? All O rings replaced on low speed and high speed screws? All choke plates equal position? Accelerator pumps free and diaphragms replaced with spring behind them? Try feathering choke when it does it. The Ski dies it is running rich, acts normal and goes it's lean. See Sticky about cleaning the ports in carb if not done when you rebuilt them.

 

[seadooxp89]

I cleaned carbs and changed gaskets and orings, we couldn't get the jets out and didn't want to strip the flat part out so we left them in but sprayed cleaner through and use a small wire brush and made sure they were cleaned. The low speeds are turned out 1 1/4 turns out spec says 1 but everyone on here said that it should be 1 1/4 to 1 1/2 turned out. The accelerator pump opened up and checked to clean inside and it was moving freely and smooth after so we didn't replace anything inside of it but we weren't sure what that did and how it worked. But when the carbs were running way too rich (due to low popoff pressure ) the problem didn't exist. That's why I'm not sure if its just the low speeds needing to be turned out more or what. If the accelerator pump wasn't working right would that only effect a tiny bit of throttle after idle?

I will try feathering the choke when i give it a little throttle and see what it does when I get a chance to get it back in the water probably wont be till the weekend sadly.

 

[seadooxp89]

I will check the transfer ports but the carbs are on the ski and its getting cold so I'm trying to avoid taking the carbs off so that if I need to I can winterize it so it doesn't get ruined during winter. Plus I don't want it to sit long with out the carbs out if you know what I mean. Is there any way to check the transfer ports while the carbs are on?

 

[670hoth]

I just bought the same ski and it would run on the trailer but not in the water when I bought it. I cleaned the carbs, replaced the fuel lines and filter, cleaned out the tank, and set the low speeds to 1.0 turns. It still ran OK on the trailer but would not start in the water. I made a good discovery and corrected it yesterday that made it run much better on the trailer. I am hopeful it will now run in the water but won't know until later on today. It turns out the oil pump adjustment was off and it was getting way to much oil. When I took the carbs off to clean them I reinstalled the cable exactly as it was so I know it had this problem when I bought it. I readjusted per the manual to line up the marks on the oil and it runs much better on the trailer. I would recommend you check your oil pump adjustment. It could cause issues such as your having. One thing to note is that my engine is old and only has 120 lbs compression. I have had two local seadoo dealers say it should still run Ok at this compression but several people on here have said it wont. We will soon find out but regardless, I know I need at least a top end rebuild to get compression back up to 150+.

 

[670hoth]

I ran my 97 XP this afternoon and although I have to hold the throttle to the bar and hit the starter button for a while when it finally starts and runs good. It seems very rich when starting and at idle and on the low end but from about 1/4 throttle up it cleans up and runs great. The oil pump is now adjusted properly, I believe it has stock pilot and needle jets, and the low speed screws are only about 3/4 turn out. I know a lot of people run these closer to 1.5 turns out but for some reason on my ski it is already too rich. I don't know if this will help you in any way but since its the same model ski and I am also working on carb tuning I thought I would share.

 

[benjilafouine]

Wrong rotary valve timing will make your engine running bad for sure. Who installed the new engine? With new engine, three things can basically go wrong:

1. bad gasket somewhere (air leak)
2. carb issue (it will make your engine hesitating and running bad)
3. timing (rotary valve) will make your engine running like hell (mine was too lean all the time). Way worse than carb issue.

Until you find your issue, when you stop testing in water, make sure your spark plugs are not too hot to burn your fingers, this way, you will ensure that you are not damaging your engine.

Also, to determine if your ski is running too rich or too lean, when it bogs down, just slightly pull the choke for a fraction of a second. If ski jumps and brutally accelerates, it is too lean. If it stalls right away, it's to rich. And you should put back the screws to normal values before you try that as you will get a more accurate diagnostic.

My knowledge is all theoretical, not hands-on.



Benji.

Benji.

 

[jhjesse]

I ran my 97 XP this afternoon and although I have to hold the throttle to the bar and hit the starter button for a while when it finally starts and runs good. It seems very rich when starting and at idle and on the low end but from about 1/4 throttle up it cleans up and runs great. The oil pump is now adjusted properly, I believe it has stock pilot and needle jets, and the low speed screws are only about 3/4 turn out. I know a lot of people run these closer to 1.5 turns out but for some reason on my ski it is already too rich. I don't know if this will help you in any way but since its the same model ski and I am also working on carb tuning I thought I would share.

Sounds like the pop off is to low. I would re check pop off pressure and most especially holding pressure. New needles and seats?

 

[seadooxp89]

How can I check the accelerator pump while the carbs are on the ski? If the accelerator pump wasn't working right wouldn't that cause a hesitation throughout the throttle ? The problem is only at right after idle on the throttle, like giving it a tiny bit of throttle and that's when it does it and then you give it a little more throttle and it takes off and moves.

 

[jhjesse]

How can I check the accelerator pump while the carbs are on the ski? If the accelerator pump wasn't working right wouldn't that cause a hesitation throughout the throttle ? The problem is only at right after idle on the throttle, like giving it a tiny bit of throttle and that's when it does it and then you give it a little more throttle and it takes off and moves.

With the flame arrestor off look down the throat of the carbs and depress the throttle to WOT. You should see a nice stream gas. If not then..........

 

[Mekanix]

The accell pump only woorks from idle to 1/4 throttle and its only a one time shot every time you apply throttle from idle..
So look down the carbs and hit the throttle. You should see a nice stream in each.
Likely you will only see a stream in one of them or not much at all. In that case clean the spray nozzles with carb cleaner untill they flow well.
I usually use a full can for each carb.
Half of the can goes through the pilot circuit.
I believe your issue is either the pilot holes still clogged or the accell pump no doing its job.

 

[seadooxp89]

So take the flame arrestor off and then just press the throttle fully down with the ski not running and I should see a stream of gas go into the carb ?

 

[Strizzo]

So take the flame arrestor off and then just press the throttle fully down with the ski not running and I should see a stream of gas go into the carb ?

yes, you'll want a small mirror since you need to see straight down into the carb throats. your rich idle and bottom end sounds like either low pop off, or your needle/seat is leaking. another thing it could be, did you replace the small lines to the accel pump and from the pump to the carb throats? there is a restrictor in the feed line to the accel pump that slows its recharge in order to give the engine time to burn off the previous squirt before shooting another in. Dr. Honda forgot about this and replaced a cut line on my carbs without moving the restrictor over and it was waaaay fat because the needles weren't closing and the accel pump was blasting a full shot every time i cracked the throttle.

 

[JJinSC]

Do check the a-pump. But if it checks out I still say turn the low speed to 1.5 on that ski and try. It will not hurt anything to try that.


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[seadooxp89]

Alright will check the accelerator pump and test in the water and adjust lows and try. I'm waiting for a some what warm weekend day to test it on the water. It's kinda getting cold fast already.