1994 GTX - Help - Ski runs great on trailer but bogs down on lake

[Jantzen333]

Hey Everyone,

I've got a 1994 GTX ski that's giving me some trouble. First, let me say I'm not a mechanic, but I'm not afraid of ripping things apart and putting them back together. With that said here is the problem and what I've done to try and fix it:

Problem:
Ski starts and runs perfect on the trailer. Idles great and you can rev the engine without any problems. However, when you put her in the water, it's a completely different story. I can typically get it started and it will idle ok but the moment you try to give it some gas it will start to bog. Sometimes if you continue to play with the throttle it will almost power through whatever the issue is and it will take off as if nothing is wrong. However that only lasts for a few seconds before it bogs again. If you keep the throttle pressed you can typically get a go, go, go, bog, go go go, bog pattern going for a few min with the go go go lasting about 8-10 seconds and the bog 2-3 seconds


What I've tried:

New battery - running a battery tender lithium ion battery that is maintained with a battery tender in the off season

Fuel lines - I've replaced the old grey lines with new but I didn't take out the fuel selector and clean it out so I will be trying that soon. However if this was the problem, wouldn't it also struggle to rev on the trailer?

Carbs - I got a rebuild kit from a local Seadoo dealer and replaced everything except: needle and seat (not included in the kit), lever, and spring. When I rebuilt the carbs, the filters were very dirty and the gaskets and plastic prices were a mess. I set the high and low speed screws according to a website that had all Seadoos listed with their specs (I can find link if needed) and aligned the oil pump line with the two marks.

Spark Plugs- the plugs are new from last year and are gaped correctly 0.05 (according to manual)


Gas - 2 years ago I pulled the take completely and emptied every drop. Unfortunately, later that year someone pulling the trailer left the gas cap off during a rainy few hour drive and overnight in the parking lot. This year, I drained 95% of the gas with a weighted end siphon pump. Now I'm running 88 oct clear (no ethanol) along with some Techron additive


After all this and many man hours I'm still experiencing issues. Any help would be greatly appreciated!

Thanks,
J

 

[mikidymac]

You need to replace the fuel selector with a new one. Cleaning them doesn't work.
You also need to replace the needle and seat. And make sure you are using a 95 gram spring in the carb.

 

[Jantzen333]

You need to replace the fuel selector with a new one. Cleaning them doesn't work.
You also need to replace the needle and seat. And make sure you are using a 95 gram spring in the carb.

Thanks for the reply! I'll get those items ordered and put them in when I feel like busting my knuckles getting those carbs out again.

Any recommendations on where to get a needle, seat, and spring? (Carb parts a la cart style)

 

[mikidymac]

OSD seadoo has all the parts.

 

[Mickirig1]

You did check the pop off? If not OSD has testers for $25. A bike air pump can be used to get air pressure for testing. You can test your fuel system for air leaks. It is easier to suck air then gas. You have to have a totally tight, no air leaks in the system to get it to run right. The repair manual has the procedure. You need a few line clamps to isolate sections of fuel / vent lines. The thru the hull vents for the system need replaced from time to time. Testing should find any defective ones. Also you might check your compression on the engine. Repair manual has the procedure. Use the search function above the page on right. Another test is to open gas cap when it is hot out. You get the hiss of pressure bleed off you may not have a leak.

 

[Jantzen333]

OSD seadoo has all the parts.

Thanks! I'll check them out.

 

[Jantzen333]

You did check the pop off? If not OSD has testers for $25. A bike air pump can be used to get air pressure for testing. You can test your fuel system for air leaks. It is easier to suck air then gas. You have to have a totally tight, no air leaks in the system to get it to run right. The repair manual has the procedure. You need a few line clamps to isolate sections of fuel / vent lines. The thru the hull vents for the system need replaced from time to time. Testing should find any defective ones. Also you might check your compression on the engine. Repair manual has the procedure. Use the search function above the page on right. Another test is to open gas cap when it is hot out. You get the hiss of pressure bleed off you may not have a leak.

I didn't check the pop off because I didn't have the tool to do so. I'll look into getting one though.

I doubt I have leaks since I've heard the "hiss" in the past and I just replaced the fuel lines with better lines and clamps.

I'll have to look through my repair manual for the processes to mention to see if I want to check that.

I tested the compression last year and I'm pretty sure it's fine, but I'll check it again.

 

[Mickirig1]

Did you read the info at top of forum about carb's? You have to make sure the low speed circuit holes are flowing cleaner. Use search function at top right of page about carb cleaning. Or read the carb section above. All the little holes need to flow cleaner to get good results. It needs to be blown out with air too.
The oil tank can leak air at a seam. At a high vacuum level, you can suck air. The pop off is a very important test of the carb's. The thru the hull vents can have problems like I said. Did you replace all the carb parts? The low speed check valve. A small oval plastic piece can be a problem. If it is not flat to the surface of the assembly it will allow the low speed circuit to load up and stall or stumble. Pull the choke when it starts the problem. If it stalls it is too rich. If it corrects problem it is too lean. You can get the crude from the carb get under check valves. If you did not clean real well. Sometimes no matter what you do to the carb or carbs you have to replace.

 

[IFD158]

Mickidymac's advice above is accurate in my opinion. I had same problem with my 96 gtx. Ski would take off for 5 seconds, then bog, and repeated.I bypassed my fuel selector temporarily and most of my bog disappeared , except slightly. I have ordered a new OEM fuel selector and fuel strainer taking his advice. Air is getting in lines and you may be running out of fuel so to speak as he told me. And thanks mickidymac for the help to me.

 

[Jantzen333]

Thanks for all the input from everyone.

Update: I pulled the Carbs out again today and did a pop off test on both carbs. Both of them popped somewhere between 27-30 PSI, which is correct according to the reference here. One of them kinda leaked if I tried to get it to hold pressure over ~20 PSI. I'm sure this is because the needle and seat weren't replaced with the rebuild. I'm going to order new a new set and replace those before I put them back in.

Unfortunately, the rotary valve came off with the carbs when I was removing them this time. So i'm also going to order a gage and put that back on according to the shop manual.

Looks like I should be setting it to 130 degrees on opening with MAG side piston at Top Dead Center.

 

[Jantzen333]

Did you read the info at top of forum about carb's? You have to make sure the low speed circuit holes are flowing cleaner. Use search function at top right of page about carb cleaning. Or read the carb section above. All the little holes need to flow cleaner to get good results. It needs to be blown out with air too.
The oil tank can leak air at a seam. At a high vacuum level, you can suck air. The pop off is a very important test of the carb's. The thru the hull vents can have problems like I said. Did you replace all the carb parts? The low speed check valve. A small oval plastic piece can be a problem. If it is not flat to the surface of the assembly it will allow the low speed circuit to load up and stall or stumble. Pull the choke when it starts the problem. If it stalls it is too rich. If it corrects problem it is too lean. You can get the crude from the carb get under check valves. If you did not clean real well. Sometimes no matter what you do to the carb or carbs you have to replace.

I didn't read the carb page here. I followed a YouTube video that seemed pretty comprehensive

https://youtu.be/Xpjqzf9CFYk

I'm pretty sure I cleaned everything out pretty well. I used carb cleaner and air to blow everything out. I made sure I could see through the jets and that carb cleaner would flow into the carb through the tiny holes. I replaced everything except needle, seat, and the single tiny plastic piece that is screwed down (not the two round plastic discs, those were replaced). The only reason those pieces weren't replaced is because they didn't come in the kit that I bought from the dealer even though the dealer said they did :/

 

[Jantzen333]

Mickidymac's advice above is accurate in my opinion. I had same problem with my 96 gtx. Ski would take off for 5 seconds, then bog, and repeated.I bypassed my fuel selector temporarily and most of my bog disappeared , except slightly. I have ordered a new OEM fuel selector and fuel strainer taking his advice. Air is getting in lines and you may be running out of fuel so to speak as he told me. And thanks mickidymac for the help to me.

I'll have to try bypassing the selector. What fuel strainer are you using?

 

[JJinSC]

OEM strainer.

 

[Jantzen333]

OEM strainer.

Are you just talking about this filter?



If so, did you replace just the filter or the whole assembly?



I was thinking about getting a new filter and o-rings, but after the comment on the fuel selector, i'm wondering if I need to replace the whole thing?

 

[JJinSC]

I still have the original of the whole thing on mine. Same o-ring and same element. If the element is not damaged, soap and water will clean it up well. Alcohol for anything that does not take off.

If you feel/see the need, replace the o-ring and element. Inspect the rest for cracks, etc. If none the rest should be fine.

 

[Mickirig1]

Take the lines off the under front hatch fuel filter. Put a piece of tubing on one nipple and block off the other with your finger. Blow into the line, able to blow air without much effort it has a leak. Use a piece of 1/4 inch brake line and splice the lines together and order a new filter from OSD.com .

 

[Matthew602]

1996 SeaDoo Bombardier fuel lines green sludge

 

[mikidymac]

Wait! You need to replace the tiny plastic film under the aluminum block that you say the kit didn't have and the needle and seats before moving forward or you will be chasing your tail.

 

[Jantzen333]

Mickidymac's advice above is accurate in my opinion. I had same problem with my 96 gtx. Ski would take off for 5 seconds, then bog, and repeated.I bypassed my fuel selector temporarily and most of my bog disappeared , except slightly. I have ordered a new OEM fuel selector and fuel strainer taking his advice. Air is getting in lines and you may be running out of fuel so to speak as he told me. And thanks mickidymac for the help to me.

UPDATE: I was able to replace the needle and seat in both carbs, replaced the fuel filter and I ring, and by passed the fuel selector switch. I couldn't replace the small plastic price under the aluminum block cuz I didn't get a one with my kit and I can't fine just that piece anywhere.

Took the skis to the lake yesterday and just like you 90-95% of the bog is gone! I only notice a little bog when turning at med-high speeds (25-30mph).

We're you ever able to get rid of the remaining bog? Also, is there really any point to getting a new fuel selector? I'm thinking about just keeping it bypassed. I never used the fuel selector anyway cuz we're pretty careful with fuel levels.

 

[Jantzen333]

Wait! You need to replace the tiny plastic film under the aluminum block that you say the kit didn't have and the needle and seats before moving forward or you will be chasing your tail.

Any idea where I could get just that film? I didn't see it in the kit I bought.

 

[Jantzen333]

Also, I had to re-time the engine since the plate came off the rotary valve when I took the carbs off. I snapped a quick pic of the plate and figured I'd see if it may be causing any of the problems.

 

[Mickirig1]

Did you try OSD.com ? Send him an E-mail. Should be able to help. Try the pull the choke a little when it bogs. May have the high speed a little high or getting a bit of load up from the little plastic check valve.

 

[IFD158]

Jantzen333 I did not resolve my bogging issue after fuel selector and strainer replacement. Exact same symptom came back. I have resorted to a local ski mechanic so that I can enjoy what's left of the summer. As soon as I hear back ,
I'll let everyone know what he found.

 

[Mickirig1]

You did not throw out a little piece in the fuel line between carbs did you? Some ski's have the restriction in line to build fuel pressure. Like I said, you have to check fuel system for air leaks. It is way easier to suck air then fuel. The fuel can splash up on fuel filter / water separator gasket under front hatch and seal it. No air leak. Then it dries out and leaks again. You jump wakes and it changes the flow. Sometimes no matter what you do you need a different carb or carbs. I ran into that problem. i rebuilt mine like a surgeon. Still would not work right.

 

[Jantzen333]

You did not throw out a little piece in the fuel line between carbs did you? Some ski's have the restriction in line to build fuel pressure. Like I said, you have to check fuel system for air leaks. It is way easier to suck air then fuel. The fuel can splash up on fuel filter / water separator gasket under front hatch and seal it. No air leak. Then it dries out and leaks again. You jump wakes and it changes the flow. Sometimes no matter what you do you need a different carb or carbs. I ran into that problem. i rebuilt mine like a surgeon. Still would not work right.

Mine didn't have anything on the grey fuel line between carbs. I was planning to test the fuel system for leaks next. I found the section in my shop manual, but I don't have hose clamps or a tester gauge. Gonna order those of Amazon soon.