*** need help with my 96 SEADOO GTI** BOGGING, hard start etc

[Lukelona]

Hey guys and gals,
Just picked up a pair of seadoos on dual trailer last week, a GTI and a SPI. Both 1996 model
The spi is a 587 motor, the GTI I believe is a 717??
The tag is missing off the engine but it's a twin cyl, with dual carb.

Anyway, rebuilt carbs n the non running SPI and it runs like new!
The GTI ran when I got it, but upon test drive it ran crappy when I put it in the water.w would scream for a sec and fall on its face, I'd pull choke little and it would open up again they bog down. Did this for about 20 min before I loaded it back up and deemed it in need of carb rebuild
That I rebuilt carbs, reinstalled, and it almost seems worse. It's hard to start after it sits for few min, and when it starts it's slow revving up.
Just doesn't seem snappy like the other ski is.
I'm gonna water test it tomorrow to get better idea how it runs.

I'm pretty sure it didn't make a big difference rebuilding carbs. It has all knew fuel lines, so not the grey line issue, fuel selector knob is broke, was thinking of deleting it completely to see if that helps.
It is low on gas that is old from last season. Has about 3" in bottom of gas tank.

Any thoughts what could be wrong? I'm mechanically inclined, and know small engine work pretty well too, only thing I'm not sure of on these is the rotary valve setup . Never messed with one.

Any tips to help out appreciated.
I have a boating /jetski trip planned for Sunday and would love to have this one running right by then!

 

[eavega]

Did you check for the specification on the pop-off on the needle valves when you rebuilt the carbs? Sounds like you might be flooding. Also check to see that the fuel pump is holding pressure, I don't know what it is on the 717 motor, but on my 657x motor the fuel system needs to hold 4 PSI for 10 seconds or longer. The procedure is in the service manual.

You can bypass the fuel selector for testing, but I would recommend making sure you either replace (preferred) or clean out the existing one if you isolate the problem to the selector.

Also, dump the old fuel. You don't know where its been!

-E

 

[Lukelona]

Did you check for the specification on the pop-off on the needle valves when you rebuilt the carbs? Sounds like you might be flooding. Also check to see that the fuel pump is holding pressure, I don't know what it is on No 717 motor, but on my 657x motor the fuel system needs to hold 4 PSI for 10 seconds or longer. The procedure is in the service manual.

You can bypass the fuel selector for testing, but I would recommend making sure you either replace (preferred) or clean out the existing one if you isolate the problem to the selector.

Also, dump the old fuel. You don't know where its been!

-E

No to either... honestly don't know how to check pop off pressure. Or see if pump holds pressure.
The pump is new, with same brand kit used on 3 other skis in last week's
I reused pop off springs that were in it already though.

UPDATE: I did test drive it today, ran better than I thought it would, but it's not right.
Starts good cold, once started harder to start after that. Have to hold gas down and crank for 10-30sec.
Then then taking off it'll go ok, but not snappy like it should be, then you'll feel it take off like hell!
Once you let off, like to do a turn around it is slow acceleration again until you hit certain rpm and it takes off again.
I don't get it....I'm getting aggrivated already lol
Please help!!

 

[Lukelona]

O also, two more things that may help...
When I got it home, I happened to remove fuel cap, and t "hissed" like it was under pressure. Did the same to the other seadoo, and it didn't do it.
My understanding is that there is tank vent lines to avoid it violating pressure correct?
Could this cause running issue?

Also, I checked the plugs after good long run, they were golden brown color. Which is usually good for a 4 cycle, but seems like that would mean it's running lean on a 2 cycle right?

What do y'all think

 

[eavega]

O also, two more things that may help...
When I got it home, I happened to remove fuel cap, and t "hissed" like it was under pressure. Did the same to the other seadoo, and it didn't do it.
My understanding is that there is tank vent lines to avoid it violating pressure correct?
Could this cause running issue?

Yeah, you need to check the vents. The fuel system is pressurized when the ski is running. Again for my 657x engine, I think the specification is that it should hold 5 PSI. The fuel system also has a check valve that needs to be inspected and a pressure relief valve. The procedure is in the "Fuel" section of the repair manual.

Also, I checked the plugs after good long run, they were golden brown color. Which is usually good for a 4 cycle, but seems like that would mean it's running lean on a 2 cycle right?

Biscuit to tan indicates that you are running well. Running lean would be closer to white, rich would be closer to chocolate. shiny and white is bad lean.

-E

 

[Lukelona]

Update-
Took out for a ride yesterday, was running OK like i said before, but again, not crisp throttle response like it should be
All of a sudden it wouldn't go over 5mph!
You could hold gas to handlebar and it just putted along.
Then changed plugs with brand new set, same thing. I removed gas cap to release pressure, no difference.
I shut it off and started it a few times, and it ran like it was before, actually going but not right.
Then right back to not revving.

Put it on the trailer for rest of the day and rode on the boat and other ski.
I checked it today and I now have the carbs back off to reinspect them. I started it in the yard today and wouldn't rev up still. I took air box off and spark arrestor, inside carbs soaked with gas. I'd say excessively wet. And plugs were wet with gas still before i started it today.
Once the spark arrestor was off it ran and reved pretty good.
But i think it's getting to much fuel . Also, noticed a gas leak on pump side of main carb. It was wet right there.
When I took the carbs off, there main fuel line was just pouring fuel. I figured it should stop after line cleared but it didn't seem to so I plugged it off for now.

I never changed the pop off springs, so I don't see how they could be wrong, but I don't have a tester so I'm not sure how I can see if they're right
I'm so lost now...idk where to start.

I guess I'm gonna tear down the carbs again and see if I missed something or did something wrong. I was kinda in a rush when I rebuilt them so it's possible

Let me know what you guys think. I appreciate your help!

 

[zdeyonker]

Running better once removing the spark arrestor indicates that it was getting too much fuel. I would fix your fuel leaks, then test the pop-off pressure. You can search youtube for a video, then either buy a tool or build your own. I made one using a small air line regulator, a fitting to connect the air hose to on one side, then a barbed fitting and a length of hose on the other to connect to the carburetor. The spring can weaken over time then allow the needle to hang open or open prematurely causing a flooding condition.

Another thing you should really check while the carburetors are off is the reed cages. The reeds should be flat on the cage and not torn, or tattered. Dip them in some thin oil and see where they are sticking to the rubber seal.

As far as the fuel flowing, you basically created a siphon. If you leave the hose low in the hull, the pressure from fuel in the tank will continue to push it out of the hose. Just plug it and raise it above gas tank level.

 

[AL.Longshot]

Double check your carb adjustments. I believe the low side should be 5/8s of a turn out and the High side should be bottomed out.