717 '96 GTI Bogging and stalling, feel like I've tried everything. :(

[lilstrudel717]

Been trying to get this ski going all summer, but I think I'm finally stumped and done dumping money into it. Bout to put it up for the summer and come back to it next year...

Here's a list of everything I've done/replaced to it now in no particular order:
engine gaskets/seals
regulator rectifier
beeper
mpem
piston rings
new carbs + carb rebuild (didnt replace needles they looked ok, did tune and set pop off)
fuel lines + filter
carbon seal drive line kit
wear ring
new battery
fixed wiring (i think)
ignotion coil & plug boots
stator

Despite all this effort I'm still having problems with the ski, bogging, rev limit (seemingly), and stalling. I've cleaned my selector, ran it on res, opened the gas cap, that's not the problem. It does seem to run a little longer if I yank on the choke intermittently while running.

Front plug is usually dry and grey, rear plug is almost always black, wet oily.

Any ideas what I should do/check next or what is going on?

edit: forgot to mention, I don't own a reliable comp tester, but my harbor freight one I bought for this reads 60/60, then another sketchy tester my dad had read 100/110 ¯\_(ツ)_/¯

 

[burtshaver2021]

Where to start…. Of the new parts you’ve put on, which are OEM and which are aftermarket, what brand are they and where did you purchase them? A lot of aftermarket electronics can cause issues right out of the box. The new carbs, are they used OEM? Did you check what size the jets were? When you were rebuilding the carbs did you follow the carb rebuild thread on here? Test the pop off? Check the fuel pump and needle for leaks as per carb thread and/or manual? When you say new fuel filter, do you mean OEM? Did you replace the fuel selector valve with a new one from a known reputable dealer? Or pressure test it? Do you have good fuel lines? I would start with a compression test from a known accurate tester for small engines, even 110/110 is very low, to low to be a a solid running machine on the water. Sounds like you are running lean on one cylinder and rich on the other.

 

[lilstrudel717]

Where to start…. Of the new parts you’ve put on, which are OEM and which are aftermarket, what brand are they and where did you purchase them? A lot of aftermarket electronics can cause issues right out of the box. The new carbs, are they used OEM? Did you check what size the jets were? When you were rebuilding the carbs did you follow the carb rebuild thread on here? Test the pop off? Check the fuel pump and needle for leaks as per carb thread and/or manual? When you say new fuel filter, do you mean OEM? Did you replace the fuel selector valve with a new one from a known reputable dealer? Or pressure test it? Do you have good fuel lines? I would start with a compression test from a known accurate tester for small engines, even 110/110 is very low, to low to be a a solid running machine on the water. Sounds like you are running lean on one cylinder and rich on the other.

All parts were OEM, except the gaskets/seals which I got from sbt, and the rectifier/mpem which I just bought cheaper amazon replacements for because I literally have no money left to spend on this ski that is probably gonna be worth less than I've spent trying to get it to run when I'm done with it lol. Rebuilding the carbs I followed a youtube video and I tested pop-off, but didnt check needle size. One thing is I did not know at the time you arent supposed to bend the lever and you are supposed to just change the spring, so I bent it to the correct popoff pressure. Not sure if that would be causing this but maybe? Never replaced selector but I cleaned and blew that sucker out good or I sure thought I did. Fuel lines are good too. If the fuel conditions are uneven cylinder per cylinder does that not suggest a carburetor problem, because that's what I feel like it has to be at this point.

 

[burtshaver2021]

It could very well be fuel, it usually is. Yes, you should never bend the lever to obtain a specific pop off, if you use a 1.2 needle with a 80 gram spring and new levers you will get the appropriate pop off, I would still verify the pop off and look for leaks at the same time. Where did you purchase the carb rebuild kit from?

 

[etemplet]

Could be the screen at the bottom of the baffle. I'm fighting the same thing for a ski I've messed with for 3 or 4 times. 2003 GTI. I've disassembled the carb 3 times just to check (the skis sits a lot) , swapped MPEMs, drained the fuel tank, renewed some of the hoses, they were not old. It runs bogs and will only idle (per owner). I rode it once for about 40 minutes with no issues. I got the ski back from its new owner and checked it. Finally I punched some holes in the filter screen.

Once I put a new screen on the bottom of a fuel baffle. The screen covered the entire round bottom of the baffle. I melted it on there. I made sure water flowed through the filter easily before I installed it and the screen spacing was "larger" than the small stuff Seadoo uses. It was a 96XP. I took it out a few times and it would shut down at the same point during my ride. Difficult to start. I could ride it half throttle all I wanted but when I went wide open it would run about1/3 mile and shut down. I noticed my fuel light would come on. So, the fuel couldn't get into the baffle fast enough at high speed. I punched some holes in it and let it eat. ran great and still does. I still can't figure out how a larger screen wouldn't flow enough fuel but I'm not arguing with results. I gave up. LOL

I restored that ski several years ago and it doesn't have a lot of time on the engine. I did replace a good fuel selector Problem with skis like this is I'm not riding them daily to figure it out so I only see it now and then.

 

[lilstrudel717]

It could very well be fuel, it usually is. Yes, you should never bend the lever to obtain a specific pop off, if you use a 1.2 needle with a 80 gram spring and new levers you will get the appropriate pop off, I would still verify the pop off and look for leaks at the same time. Where did you purchase the carb rebuild kit from?

It was a mikuni kit from amazon. If I effed that up I'm gonna be ticked as those kit weren't cheap lol. The needles looked to be in good condition when I disassembled the carbs, but like I said I'm no expert so maybe I should have just changed them anyways.

 

[etemplet]

It was a mikuni kit from amazon. If I effed that up I'm gonna be ticked as those kit weren't cheap lol. The needles looked to be in good condition when I disassembled the carbs, but like I said I'm no expert so maybe I should have just changed them anyways.

Does the diaphragm have a red disc on the top? The part that contacts the fuel arm. If that isn't red, it's not Mikuni and that will definitely affect how the ski runs.

 

[etemplet]

Not that I do it with jet skis but it's cool buying stuff from guys like you. You've already checked everything 10 times and replaced parts, spent the money. All I have to do is find out what's wrong and I got a great ski. LOL Good Luck. Don't let it win.

 

[burtshaver2021]

It was a mikuni kit from amazon. If I effed that up I'm gonna be ticked as those kit weren't cheap lol. The needles looked to be in good condition when I disassembled the carbs, but like I said I'm no expert so maybe I should have just changed them anyways.

I doubt you effed anything up, but if you do the tests mentioned in the manual and carb rebuild thread, just verify the jets since you bought a new carb and set the screws to factory settings , put the proper spring in and new lever since it’s been bent, I find everything works out if you follow those steps.

 

[Noahsfixingbrokedownskis]

I had the same ski and had the same problem. Tow the ski to AutoZone or similar and borrow a legit compression tester and test the compression. Most chain auto parts store have a tool loan program where they will loan you a compression tester for free. Bad compression won't run a machine. So test that first. If that is ok the issue my by like what occurred to me. On my ski my issue was the three holes in the cab never got totally clean when I first rebuilt it using a Mikuni kit. The Mikuni kit is only part of the solution. The full solution for me was recleaning the the three holes by blocking each off and running cleaner through each until unblocked. Follow the carb rebuild guide exactly. If you have already done that than Start the engine on land and place a voltage meter on the battery, rev the engine. You don't want to see high numbers above 14 volts when this revs. This indicates a bad voltage regulator. Even though you replaced it, it could be a bad replacement. Bad voltage regulator made my ski stumble and would not allow me to rev in water. It acted like it wouldn't go above 5500 rpm. The final recommendation is to check the fuel filter a bad gasket on the lid can allow air in and make it run like crap.

 

[lilstrudel717]

Not that I do it with jet skis but it's cool buying stuff from guys like you. You've already checked everything 10 times and replaced parts, spent the money. All I have to do is find out what's wrong and I got a great ski. LOL Good Luck. Don't let it win.

Ahahaha yeah thats why I can't sell it I'm in far too deep... the most important thing this ski taught me is next ski I am 100% not using the shotgun method to fix it

 

[lilstrudel717]

I just went to O'Reilly's to use their compression tester... 105 PSI on the front and 95 on the back, so yeah. Looks like I've definitely got some low compression. Sort of just wondering now if the low compression is directly causing my problems or just making them worse. Need to figure out what's causing the compression. Or should I just say to hell with it all and rebuild it? I'm worried the crank seals may be my problem.

 

[burtshaver2021]

You have to rebuild it, but you should do a leak down test before disassembly. You will need to go through the carbs as well

 

[lilstrudel717]

You have to rebuild it, but you should do a leak down test before disassembly. You will need to go through the carbs as well

Thanks for the help I appreciate it. This may be a dumb question but if I'm already rebuilding it what info exactly would the leakdown test tell me or what would I be looking for?

 

[burtshaver2021]

It would tell you if the outer crank seals or if thr intake manifold o ring was leaking.

 

[burtshaver2021]

Thanks for the help I appreciate it. This may be a dumb question but if I'm already rebuilding it what info exactly would the leakdown test tell me or what would I be looking for?

And there’s no dumb questions