1997 GSI bogging issue

Papa Romano

Papa Romano

Member
Hello, I’ve been trying to figure out this issue for a while and finally decided to join the forum because I’m about to give up. I apologize for the long post in advance but I want to provide as much info as I can to avoid guesswork.

I have a 1997 GSI and 1997 GTI. They both have the same 717 engine and single carb. Both ran great last summer with gray fuel lines. Compression on GTI is 135, 145 psi, compression on GSI is 140, 150 psi.

Over the winter I did the exact same preventative maintenance on both skis - by replacing the gray fuel lines, replaced water separator assembly, fuel selector, carb gasket, and cleaned/rebuilt both carbs with the correct mikuni kit, set the high and low speed screws to manual specs (L - 1 3/4, H - 0), and checked pop off which was in spec.

The GTI runs like a dream, it’s exactly what I expected it to run like after the maintenance. However, the GSI keeps having issues with bogging at 75-100% throttle. Idles at 1500 in water. It is slow to accelerate, but when it finally reaches 6300ish rpm, it will bog to 4500 and then back to 6000+. After reading all kinds of forums, I have been messing with the low/high speed screws with no success. Can’t figure out why this one has issues when the other one feels perfect, when they both have the same parts, rebuilt the same way. I did find an exhaust leak, which has a temporary patch with JB weld exhaust paste, which seems to be holding up well. It made some improvement but still had bogging issues.

After reading more forums, in the GSI only: I installed a check valve in the fuel line going into the carb, i replaced the coils, spark plugs (gapped correctly), and I bit the bullet and rebuilt the carb again, this time with OSD’s back to OEM kit, which replaces the needle, seat, spring, and others. First run was much better, no bogging at WOT, but still slow to accelerate. No big deal, I’ll do some H/L screw tweaks over time. This weekend, it starts bogging at WOT again. I started turning the screws in small increments but nothing seems to be improving.

Again, sorry for the long post but I’m running out of ideas! Maybe I have an air leak somewhere? Should i swap the GTI and GSI carbs to see if the issue follows the carb? Any help would be greatly appreciated! Thanks in advance.
 
Last edited:
If they are the same carb then yes you can swap them if you want to rule out if it is the carbs or not. If that doestn work is most likely your rotary valve timing is off or the clearance is not in spec.
 
2strokeboy said:
If they are the same carb then yes you can swap them if you want to rule out if it is the carbs or not. If that doestn work is most likely your rotary valve timing is off or the clearance is not in spec.
Click to expand...
Thanks for the reply. This is the first time I’ve heard of a possible engine related issue instead of a carb/fuel supply issue. So I’m curious, if it was running great thru last summer, but having issues on day one this spring, can the rotary valve timing be affected without touching the engine at all? How does it get thrown off? I don’t want to rule it out as a possibility (because I’m still new to this, so I’m all ears) but it also just seems unlikely based on the sequence of events. I’ve never cracked the engine open, so if the rotary valve can be affected externally that would be really good information to know so I can try to avoid that in the future. Thanks!
 
burtshaver2021 said:
When it starts bogging try pulling the choke to see if this improves it, possible air leak somewhere
Click to expand...
I have tried that actually. Sometimes that trick works, but after I go make a screw adjustment, seems like something else gets worse. Kinda going in circles.

Is it possible to over tighten the carb to the engine intake and damage the gasket? I didn’t think I tightened too much, but maybe it’s possible. Seemed like the previous owner used some type of silicone gasket for some reason
 
Papa Romano said:
I have tried that actually. Sometimes that trick works, but after I go make a screw adjustment, seems like something else gets worse. Kinda going in circles.

Is it possible to over tighten the carb to the engine intake and damage the gasket? I didn’t think I tightened too much, but maybe it’s possible. Seemed like the previous owner used some type of silicone gasket for some reason
Click to expand...
It should run good at factory settings, if pulling the choke helps when the high and low are set to factory settings I would check for air leaks, try bypassing the fuel filter and fuel selector for valve by running the line that comes from the carb inlet fitting directly to the ON fitting in top of the fuel tank, if this doesn’t help maybe the fuel lines are sucking in some air, are they good black lines with a 1/4” ID? Possibly the carb gasket is leaking, could replace that and put a thin thin layer of 518 on each sides of the gasket. Could also be leaking crank seals, you could check those with a leak down test.
 
burtshaver2021 said:
It should run good at factory settings, if pulling the choke helps when the high and low are set to factory settings I would check for air leaks, try bypassing the fuel filter and fuel selector for valve by running the line that comes from the carb inlet fitting directly to the ON fitting in top of the fuel tank, if this doesn’t help maybe the fuel lines are sucking in some air, are they good black lines with a 1/4” ID? Possibly the carb gasket is leaking, could replace that and put a thin thin layer of 518 on each sides of the gasket. Could also be leaking crank seals, you could check those with a leak down test.
Click to expand...
That’s a great idea, I will definitely try bypassing those next and see what happens.

And yes the fuel lines are 1/4” ID, top rated ones on Amazon, probably middle of the road in terms of quality. However, have you heard of fuel lines causing gas to turn orange? When I open up my carb, the fuel is orange instead of clear. The fuel in the filter is clear. But again, the GTI has the same fuel lines and doesn’t have issues.
 
Papa Romano said:
That’s a great idea, I will definitely try bypassing those next and see what happens.

And yes the fuel lines are 1/4” ID, top rated ones on Amazon, probably middle of the road in terms of quality. However, have you heard of fuel lines causing gas to turn orange? When I open up my carb, the fuel is orange instead of clear. The fuel in the filter is clear. But again, the GTI has the same fuel lines and doesn’t have issues.
Click to expand...
Yes I have, I ordered the same line from amazon and then read the reviews Lol, turns the fuel orange and three lines get brittle and crack in months.
 

Attachments

  • IMG_5316.jpeg
    IMG_5316.jpeg
    362.3 KB · Views: 4
burtshaver2021 said:
It should run good at factory settings, if pulling the choke helps when the high and low are set to factory settings I would check for air leaks, try bypassing the fuel filter and fuel selector for valve by running the line that comes from the carb inlet fitting directly to the ON fitting in top of the fuel tank, if this doesn’t help maybe the fuel lines are sucking in some air, are they good black lines with a 1/4” ID? Possibly the carb gasket is leaking, could replace that and put a thin thin layer of 518 on each sides of the gasket. Could also be leaking crank seals, you could check those with a leak down test.
Click to expand...
If I try this fuel filter/selector bypass, should I use a new fuel line since mine is apparently questionable? Is there a big risk of damaging the carb when running w/o the filter ?
 
Papa Romano said:
If I try this fuel filter/selector bypass, should I use a new fuel line since mine is apparently questionable? Is there a big risk of damaging the carb when running w/o the filter ?
Click to expand...
Good idea, yes use a new piece of fuel line for this. No risk to the carbs, the micro filter in them will catch any debris that could be present. There is a risk of trying to burn water if there was water in the fuel
 
burtshaver2021 said:
Good idea, yes use a new piece of fuel line for this. No risk to the carbs, the micro filter in them will catch any debris that could be present. There is a risk of trying to burn water if there was water in the fuel
Click to expand...
I haven't been able to trial the water separator/fuel selector bypass yet, but I went ahead and replaced all of the fuel lines with a clear, reinforced fuel line. Seems like it will hold up well, hopefully better than the clear Tygon line that some people use. I also put some gasket sealant around a new base gasket, as well as around the threads of the water separator. Replaced the fuel selector too with an OEM one (I think it's OEM but feels like higher quality regardless). Sprayed soapy water and blew air into them to check for leaks and couldn't find any. Ski started right up and no more orange fuel (now that I can see into the fuel lines). So I will take it for another test ride before trying the bypass test.

I couldn't see any air bubbles going into the carb, but I was able to see an air bubble in the return line just outside the carb going to the tank. Is this normal? I only ran the ski for a few seconds after getting the fuel cycled thru the lines, so I guess it's possible that it's still just getting air out of the system? Wondering what your thoughts are. Thanks
 
Last edited:
Papa Romano said:
I haven't been able to trial the water separator/fuel selector bypass yet, but I went ahead and replaced all of the fuel lines with a clear, reinforced fuel line. Seems like it will hold up well, hopefully better than the clear Tygon line that some people use. I also put some gasket sealant around a new base gasket, as well as around the threads of the water separator. Replaced the fuel selector too with an OEM one (I think it's OEM but feels like higher quality regardless). Sprayed soapy water and blew air into them to check for leaks and couldn't find any. Ski started right up and no more orange fuel (now that I can see into the fuel lines). So I will take it for another test ride before trying the bypass test.

I couldn't see any air bubbles going into the carb, but I was able to see an air bubble in the return line just outside the carb going to the tank. Is this normal? I only ran the ski for a few seconds after getting the fuel cycled thru the lines, so I guess it's possible that it's still just getting air out of the system? Wondering what your thoughts are. Thanks
Click to expand...
I wouldn’t be concerned with an air bubble in the return line
 
What fuel line did you use?
Never seen any clear line that lasted for more than a couple years.
Also no sealant around the fuel seperator, it has an o-ring.
 
Papa Romano said:
Amazon.com
I just need it to help diagnose my bogging issues and get me thru the summer. I'll be replacing it with much higher quality hose later.
Click to expand...
Not sure if it’s just me or not but every time I have a machine with clear lines I have to change them out because I can’t get them to seal . Any machine I’ve gotten that’s had spark and compression new fuel
Lines if required, new oring in the fuel filter, new fuel selector valve and a new back to OEM carb rebuild kit from OSD has been the Mikuni miracle. Now if you you have an inexpensive tool to apply vacuum and pressure you can test the valve for leaks but it could Still be clogged and if it runs right with a direct fuel
Line from the tank then no need to rebuild the carbs in my opinion. The continental fuel
Line is available on amazon for around 50.00 for 25’
 
Check for compression first and rule that out.
I doubt it’s the battery,,, but you would be surprised,, so do a load test on the battery,, those are always my 1st two moves.
If the carb is off, it will initiate symptoms right away.
 
You must log in or register to reply here.

Similar threads

J
1997 seadoo gsi fuel issue
Replies
6
Views
295
burtshaver2021
burtshaver2021
D
97 GSI drive shaft issue
Replies
0
Views
64
Drollo42
D
S
Looking for a “cruiser” that can “legally” pull a tube.
Replies
12
Views
188
mikidymac
mikidymac
A
97 GTX idles but dies with throttle
Replies
3
Views
75
aklaybzee
A
M
1997 GTI Stall Issue
Replies
5
Views
136
mikidymac
mikidymac
Back
Top