1996 GTS Carburator Bogging

[zurod1]

My 1996 GTS SeaDoo had been parked for about 6 years due to a bogging problem, during that time I had replaced the fuel lines. Last fall I removed the carb and found the pump filter was clogged. This spring I put it in the water and ran great for about 15 minutes, then bogged and died. Thinking something must have plugged up I pulled the carb again and installed a carb Winderosa kit. This is where my trouble really started, I lost the needle valve spring (never do a carb kit on a picnic table in the sand), the kit I purchased came with 4 springs, I picked a spring and put the carb back in. At this time I noticed spring was not properly on the oil pump lever and was just rolling around, I must have taken it off for some reason I don't remember. I fixed this, when I checked the plugs they were wet, after a long period of starting and cleaning the plugs I got the Seadoo running and the oil out. Now when I rev up the engine it just bogs. I have tried all 4 springs and did a "pop off test" and appears to be in the range with the longest silver spring.

I'm sure my problem wasn't the carb, but the oil pump spring.

Any suggestions on what I have may messed up doing the carb kit? FYI, I did remove and clean the two jets.

 

[noviceskier]

Suggestion is to use the actual mikuni kits, when doing carbs for my hx I skipped the hassle of messing with the aftermarket kits. There's a carb rebuild sticky on the forum to help guide you through the process.

 

[zurod1]

I ordered the kit recommended in the carb rebuild sticky. In the meantime, I may try putting back in the original parts.

 

[POPPS]

Have you done a compression check?

 

[noviceskier]

Have you done a compression check?

sounds like it is being flooded

 

[zurod1]

Thanks for the responses. I haven't done a compression test, but the engine was replaced and only has a few hours on it.

It did flood once while attempting to rev it up, I had to hold throttle wide open to get it started again.

Is flooding caused by a problem with either the Needle Valve, spring or diaphragm? I noticed when I put it back together and aligned the Needle Valve Leaver, it was way out.

 

[zurod1]

I put back the original valve needle diaphragm and pump diaphragm. Ran the tests as described in the carb cleaning sticky. And everything seems to be okay, but back on the machine still no power. If I slowly rev up the engine, it starts stuttering at 1/2 - 3/4 throttle, but if just quickly open the throttle it dies. I checked the plugs and appear to be dry.

The pop off test for the '96 GTS 21-37 PSI, it pops at 25 PSI. Is it possible I still have the wrong Valve Needle spring? I have the Mukini carb kit coming but won't be here till the end of August and think I may need to find the valve needle spring. My searching has ended in frustrated results, our local dealer indicates they are no longer available.

Any suggestions would be greatly appreciated.

 

[JeremyD615]

Your dealer just doesn’t want to go through the trouble unfortunately. The springs are still available, and you can get the from OSD parts. You really need to wait until you get the Mikuni kits. You’re risking the motor running it with the aftermarket stuff in there. Fuel issues are the number one killer of these skis, so make sure you don’t cut any corners there!

 

[POPPS]

Most often when I am trouble shooting a carb issue, where If I quickly open the throttle, it feels/sounds like fuel starvation, this is my sequence of diagnosis. I always start at the bottom of the pick up, I remove the inline, and reserve line from the top of the fuel pick up, attach a long (proper sized hose, doesn't have to be fuel line) , and slowly blow thru them with my mouth, (compressed air can blow off the filter mesh, which I am trying to clear).

Next, I remove inline at the of the fuel pickup that goes to the petcock, then I remove the out line coming out of the fuel filter (which goes to the carb), and attach it to the line that I removed from the inline at the fuel pick up, this allows me to totally bi-pass the petcock. Therefore, if the fuel starvation problem continues, your problem now has to be at the carb, ( assuming you do not have the gray fuel lines, which of course will partially plug up your carb).

Your symptom of the engine dying when you open the throttle, can occur from the popoff being too high, which as you know already appear to know, is from the spring being too high, and or the seat being too small. And of course this assumes you have gone thru the carbs properly.

 

[zurod1]

Okay, got my new Mikuni Carb kit, followed the garb cleaning sticky. All pressure tests worked and pop off of 27PSI was within the range of 21 to 37 sustained at 20PSI. Set the high speed idle adjusted to fully closed and low speed idle set to 1 1/4 turns back from closed.

Back on the Sea-doo, once warmed up I was able to rev up the engine. But when I turn it off and try and restart I think it floods. Very difficult to start, plugs were wet too. Got it started a couple of times same thing. I checked the oil pump linkage everything seemed ok.

Also to note during the cleaning process of the pilot circuit I really couldn't see the 3 holes he was referring to. When I sprayed carb cleaner into it I could see a spray coming out. I used an air compressor to blow through the circuit so hopefully it was clear.

Could this be related to my needle valve spring, since I lost the original and not 100% sure of what's on there?

Any other suggestions?

 

[noviceskier]

get the mikuni spring

 

[POPPS]

When you rev and say it bogs, is it a rich bog, needs to clean itself out, or a lean bog, starving for fuel?

 

[zurod1]

Just an update, I did find and install the correct spring. It is running better but hesitates and almost dies before accelerating. It was really bad the first few short runs, but does seem to get better the more I run it. I would like to have run the full tank of gas but it's starting to get way too cold.

Pulled the Seadoo out for the season, will try again next year.

Thanks all for the help

 

[noviceskier]

tune the carb with a full tank of gas

 

[zurod1]

tune the carb with a full tank of gas

When you say tune the carb are referring to adjusting air mixtures on the low and high idle? Or is there something else I should be trying?

 

[POPPS]

You don't really tune a stock 2 stroke seadoo ( unless you are racing) , Your symptoms for sure, seem fuel delivery. Did you clean both micro filters? Did you rule out the fuel pick up and fuel selector? Is the fuel bowl FULL?

 

[Madpaddler]

Listen to POPPS, the bowl he's referring to is the filter bowl under the "dash". An air leak at it's O-ring and/or a gummy or faulty fuel selector has been the issue for many a SD owner.