Won't Run

[Solo2882]

I’d like to get some advice from everyone here. I have a 1997 Sea-Doo GTX. I rebuilt the dual carburetors using OEM carb kits with new needles and seats. I checked the pop-off pressure, and it’s at 30 psi. There are no leaks. Ever since I rebuilt the carburetors with OEM parts, being advised to never use aftermarket ones, I haven't been able to get the ski to run.

I've replaced all the fuel lines and the fuel filter. I also pulled the pickup manifold out of the fuel tank to ensure all the lines were in the correct order and nothing was plugged, but the engine still doesn’t want to run. I rebuilt the engine last summer, and it ran great until I decided to rebuild the carburetors. Since then, the machine hasn’t run. I’ve taken the carburetters apart four times to ensure nothing was wrong. I even put them in an ultrasound cleaning machine to get rid of all possible debris. Sometimes It will fire up for a minute or two and sometimes it will only run for a couple seconds and then sputter shut off. It was over fueling now I think it’s under fueling. I don’t get it other than there’s something else going on that I’m overlooking. Hi Jets are set right out of the book, at zero turns and low jets are set at one full turn. Any suggestions would be great?

 

[burtshaver2021]

If it ran perfectly before you rebuilt the carbs and changed the fuel lines I would have a 2nd or 3rd look at your fuel line routing. If the fuel line routing is for sure correct then have another look at the carbs. Did you check to see if it holds pressure after it was all back together and also check that the fuel pump diaphragm is holding 4 pounds of pressure.

 

[Solo2882]

Fuel lines are differently routed correctly. I’m wondering if a blown or burnt engine would cause these symptoms? Like if I was running to lean last time, I heard that can damage the engine, the last time I had it on the water it had no power would just bog down no power in the water, that’s why I’m like oh needs a new car kit, but the last 2 runs before that it ran like a top.

 

[burtshaver2021]

Fuel lines are differently routed correctly. I’m wondering if a blown or burnt engine would cause these symptoms? Like if I was running to lean last time, I heard that can damage the engine, the last time I had it on the water it had no power would just bog down no power in the water, that’s why I’m like oh needs a new car kit, but the last 2 runs before that it ran like a top.

For sure, better check compression then

 

[2strokeboy]

Does it run if you put some fuel in the spark plugs

 

[Solo2882]

I had it running for five minutes on a garden hose. Then, I put the airbox back on it and took it to the river, but it just bogged down and over-fueled, causing the spark holes to spit fuel everywhere. I took the carbs off last time, made sure everything was seated properly, and ensured the diaphragm was working correctly on the fuel pump. I haven’t tested the fuel pump yet, and I know it's supposed to hold five psi. I think the diaphragms were a little too heavy or thick, so I put the original ones back in. Now, instead of over-fueling, it's under-fueling. I think I have too much tension on my needle and seats. now I’m worried that I wash the cylinder walls out because of all the over fueling. I’m going to do a compression test on it this afternoon. just gotta find out what psi I’m looking for?

 

[2strokeboy]

Make sure the high and low speed screws are set to the right settings. carb Reference the number is how many turns out from all the way in.

 

[Solo2882]

Make sure the high and low speed screws are set to the right settings. carb Reference the number is how many turns out from all the way in.

According to the manual. I didn’t go off the carb manual, but maybe I should but according to the Sea-Doo shop manual zero turns for high and one full turn for low?

 

[burtshaver2021]

Don’t go off the shop manual for carb settings, they are usually whacked for whatever reason, use from seadoosource.com

 

[Solo2882]

I'm getting 135 PSI per cylinder

 

[Noahsfixingbrokedownskis]

First leave the carbs on the ski and remove the line from the pump to the engine block which is on the fuel pump carb. Many forget to put that line back on when putting the carbs back on the ski. When you remove that line make sure there are no obstructions in the line or nipples. That line pressurizes the fuel pump on the carbs. The ski wont run with out this line or if its clogged. If that's fine replace it and secure with hose clamps than remove the fuel filter and dump fuel and clean. Make sure the o ring is good on the fuel filter. Replace the empty fuel filter and crank the ski. Next take the fuel filter off again to insure its pulling fuel to the carbs, it should be full of fuel. Next I would replace the fuel selector. Next I would pull the carbs after cranking. First check the carb without the fuel pump on it. Is there gas in it at all? If not replace the fuel pump side gaskets entirely and make sure to pay special attention to the two small clear disks on the pump side. To replace these easily I use dental floss and wrap it around the small plastic center of the clear disc and use it to pull it through the disc. When doing so make sure that the Mark is up on the clear plastic discs. While the carbs are off make sure to remove and clean the jets. Next make sure to remove the low-speed screw on both carburetors completely and blow the carburetors out with carburetor fluid and then air. After that is initially done put the low speed screw in and turn only one turn once it starts turning in. Use your carburetor cleaner and from the jet screw side spray cleaner into the jet opening. You need to make sure that fluid is coming out of the larger hole and the smaller holes as shown in the official carb rebuilding thread. If you dont do that the ski will not run correctly.

 

[RG123]

First leave the carbs on the ski and remove the line from the pump to the engine block which is on the fuel pump carb. Many forget to put that line back on when putting the carbs back on the ski. When you remove that line make sure there are no obstructions in the line or nipples. That line pressurizes the fuel pump on the carbs. The ski wont run with out this line or if its clogged. If that's fine replace it and secure with hose clamps than remove the fuel filter and dump fuel and clean. Make sure the o ring is good on the fuel filter. Replace the empty fuel filter and crank the ski. Next take the fuel filter off again to insure its pulling fuel to the carbs, it should be full of fuel. Next I would replace the fuel selector. Next I would pull the carbs after cranking. First check the carb without the fuel pump on it. Is there gas in it at all? If not replace the fuel pump side gaskets entirely and make sure to pay special attention to the two small clear disks on the pump side. To replace these easily I use dental floss and wrap it around the small plastic center of the clear disc and use it to pull it through the disc. When doing so make sure that the Mark is up on the clear plastic discs. While the carbs are off make sure to remove and clean the jets. Next make sure to remove the low-speed screw on both carburetors completely and blow the carburetors out with carburetor fluid and then air. After that is initially done put the low speed screw in and turn only one turn once it starts turning in. Use your carburetor cleaner and from the jet screw side spray cleaner into the jet opening. You need to make sure that fluid is coming out of the larger hole and the smaller holes as shown in the official carb rebuilding thread. If you dont do that the ski will not run correctly.

This is good advice. First off, did you follow the carb rebuild thread exactly? I know you've gone through them a few times already, but it's really easy to miss things. I have 2 96 GTX's and know this from experience.
1. Check your needle seat size, make sure its the same listed on seadoosource (1.5) and spring (80g). Also, general consensus on pop off for our machines is around 38psi (and what seadoosource recommends). Are your pilot and main jet sizes correct?
2. Perform each of the 3 tests listed in the shop manual. You will check for leaks at the needle, in the pump assembly, and also check the pump valve operation. If you find a leak, carb will not operate correctly.
3. Pump operation: Just know, that in the manual it's confusing how you check the pump valves. Our pumps have 2 outlets that are next to each other coming off the pump body (despite the stamping on the pump cover showing one in and one out) and one inlet. One goes to the PTO carb, and the other goes to the fuel return line. Test the pump diaphragm operation (the clear discs held by the rubber grommets) by connecting a tube to the fuel inlet and use your mouth to apply negative and positive pressure (should release on positive pressure, and hold on negative). Pull the tube off the inlet, and then connect it to one of the outlets. Plug the other outlet with your finger. Do the same thing, and the pump should release on positive pressure, and release on negative pressure (opposite of the inlet, makes sense...). If there is no blow-by with your diaphragms, your needle valves passed the leak test, and the pump body holds pressure as detailed in the manual, then the problem shouldn't be in the carbs.
4. Make sure the carb gaskets don't fall off and disappear when you go to mount them.
Go slow, be methodical, you'll find the problem I'm sure.

 

[Solo2882]

I actually got it running yesterday and took it to the river. Not a lot of power tho I think I need a new impeller and wear sleeve and my driveshaft may be unbalanced or bent, vibrates like a son of a bitch at a certain RPM and it took out my carbon seal, I replaced the wear ring last year but I think I am going to pull the trigger on a new impeller wear sleeve and bearing kit. Obviously also check my driveshaft alignment to the engine. thanks for all the good advice guys. I still think the carbs need some fine-tuning, but I don’t know or how a person would do that especially, with the thing sitting in the water. Those jets are pain to get at even with the air box off. Also is 135 psi Compression good?

 

[burtshaver2021]

I actually got it running yesterday and took it to the river. Not a lot of power tho I think I need a new impeller and wear sleeve and my driveshaft may be unbalanced or bent, vibrates like a son of a bitch at a certain RPM and it took out my carbon seal, I replaced the wear ring last year but I think I am going to pull the trigger on a new impeller wear sleeve and bearing kit. Obviously also check my driveshaft alignment to the engine. thanks for all the good advice guys. I still think the carbs need some fine-tuning, but I don’t know or how would a person would do that especially, with the thing sitting in the water. Those jets are pain to get at even with the air box off. Also is 135 psi Compression good?

Maybe take the driveshaft out and roll it on the flattest thing you can find, like an old window, mind you. I guess most people don’t have an old window around

 

[Solo2882]

Maybe take the driveshaft out and roll it on the flattest thing you can find, like an old window, mind you. I guess most people don’t have an old window around

Yes, I did that last summer and it seemed to be pretty straight. So hopefully it’s just out of alignment because I did move the engine around a bit this year when I pulled the front cover off.

 

[Solo2882]

Without the driveshaft alignment tool, I wonder if there’s any tricks a person can do to perfectly align the engine with the pump

 

[Solo2882]

Also has anyone tuned these carbs in the water and what were your settings? From the mikuni manual both low jets at one turn and hight jet on pto carb at half turn. Meg carb hight jet at 0 turns.

 

[RG123]

There is lots on info on the forum about tuning the carbs. Look at the sticky section first. Check seadoosource.com for the adjustor settings and jet sizing.

 

[burtshaver2021]

Also has anyone tuned these carbs in the water and what were your settings? From the mikuni manual both low jets at one turn and hight jet on pto carb at half turn. Meg carb hight jet at 0 turns.

That’s what’s on Seadoo source as well,