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  1. #1
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    GP1200r, Need Help plz

    RD Ride plate
    RD Intake Grate
    RD D-Plate
    RD Pump Seal Kit
    Riva Power Pentum Flame Arrestor
    Riva Free Flow Exhaust
    Riva Reed Stuffers
    Jetted Carbs with no choke plates or accelerator pump
    Primer Kit

    Right now:
    Low Speed: 1
    High Speed: 1 3/8
    120 Main
    110 Pilot
    95g Spring
    1.5 Needle and Seat

    Hey guys hows it going, i am having some trouble with my ski and im starting to get the feeling that just tuning the carbs wont get the job done. I re-adjusted all my settings again and still ended up only a little better than last time. I dropped my lows back down to 1 in hopes of removing the bogging issue off the line. If i punch it from standstill the ski will stall. If i slowly increase the throttle it will go fine. It used to die if you hit the throttle anywhere from 4.5k rpms or lower. Now i can nail the throttle at around 3.5k rpms and not stall. So turning in the lows a quarter turn helped a little. Though, i am still having rough starts after idling/running the ski and then shutting it down for a minute or two and no throttle response on the low end. The top end is running fine, though on my high speed test i noticed the plugs were a little black and rich though i was runnning at 7k rpms at full speed on the ski's Tach. Top end seems normal even though when i tested it on the GPS today i maxed out at 56.7mph. Last year i hit 62mph on the same GPS with a TOTALLY stock ski with broken cat and stuck acc. pump etc.... My impeller is stock, and i know thats limiting me at top end... but why would it drop me 5.3mph if it is in the same condition as last year (i checked the impeller and it is in decient condition with no major dings etc..) I was also told that i shouldnt be running a free flow exhaust without a high compression head? My heads are stock, but last year when i checked compression it was a little over 120... between like 121-122 which is still relatively close to stock. I've exhausted all my options and i am stuck. Is my jetting wrong for my mods? should i rejet or get new springs etc.... or should i just go and buy the high performance heads from riva/rd and get up to 140-150 lbs compression. I could really use the knowledge of GREENHULK right now, im starting to get depressed.

    *Note* My ski has 188hours on it*

    Thanks guys.
    Last edited by Coveted; 08-04-2008 at 08:22 PM.


  2. #2
    WATER WOODY's Avatar
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    check pm

  3. #3
    Ramps's Avatar
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    Thumbs up Hhhmmm....

    I have the same ski with the same carb settings and most of the same mods + an R&D head so I am attaining 145 comp. I think you are dealing with a fuel problem or something just sticking or not opening when it should. What is your pop off pressure on your carbs and have you completely tore them down and cleaned them very well especially if you ride in salt water.....Goodluck and keep us posted...

  4. #4
    Banned User
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    These are actually brand new carbs from Earl on these forums which came from freshwater. I tore the left side of the carb down to install my new jets and spring... but never checked the other side of the carb where the fuel diaghram is. I just went with Earls word that these were mint, which they sure as hell look like from what i have seen. Woody told me that it might be my fuel flapper down in the gas tank that is causing my issues.... you dont think not having a high performance head would affect the way i come off the line with these mods? What head did you purchase? when did you install it compared to your other mods? did you need to change the jetting after you installed it? did you see a big improvement? Do you need the girdle kit, and do you need new gaskets when installing? I'm thinking about getting it... any information on it would be great.

    Thanks.

  5. #5
    Where are you loacted? maybe someone local to you can meet with you. No GPR should ever run that slow, something is wrong IMO.

    If you can rebuild your carbs, you can pull the PV covers and inspect. It's easy and all you need is a 10mm socket/wrench and some good allen wrenches. When I checked mine I opted to disconect the cables and rotate the valves by hand so I could feel the drag if any. That's how I found out my ski had a problem developing.

    Your carbs could be having some issues, maybe a gasket isn't seated correct or? I would consider purchasing a pop-off tester as well. How did it run before the mods? Complete your prfile information with a few details and you may find some of us are local.

    Kelvin
    N.CA

  6. #6
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    I am located in Long Island, NY (The Hamptons) about 1 1/2 hours away from the infamous Carl from Island Racing.

    Before i did the mods my jetski ran great... but the first day i brought it out this summer i was riding around a little bit when i got an overheating issue and my ski shutdown. I tried to run it a little more and i lost a lot of throttle response and power. It was bogging bad. I thought something was wrong with my carbs... so i brought it in and tore it down to find that my Cat totally burnt apart and fell into my exhaust causing these issues. While everything was torn down i decided i would have my marine mechanic buddy help me with my carbs and rebuild them etc... So goes this never happened and he just totally blew me off which is when i turned to greenhulk. I was starting to tear them down when i realized all the screws were real stripped and they were in bad condition from whoever touched it before me. Luckily i came across a guy name Earl from these forums who sent me his set of carbs totally rejetted with no acc. pump choke plates from fresh water in GREAT condition for only 400$ which at the time was less than it would have costed for a marina to rebuild them merely to stock with no adjustments at all. He also sent me flame arrestors, free flow exhaust, and reed stuffers. On top of that i ordered my plat, intake, d-plate, and pump seal kit. Got all my parts installed new jets into the carbs for 120m, 110p, 95g, and 1.5 n/s then turned out the highs to 1 3/8 and the lows to 1 1/2. I tested it out it ran good on the top end but bogged out on the low end. So i turned my lows down to 1 and it runs a little better but i will still stall if i nail the throttle on the low end. So now i am stuck and dont know what to do.... I dont think adjusting my needles is going to help me. Either my jetting is wrong, i need to recheck all my carbs, or i have a fuel flow issue (though the ski seems to be bogging meaning i would have too much fuel? when i punch the throttle from stand still it just dies straight out.... no bogging for a few seconds then taking off unless i hit the throttle from like 2-3k rpms in which it will then bogg a little then take off)

  7. #7
    Moderator beerdart's Avatar
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    Check your pop-off you may have a leaky NS. I have a similar set-up on my 1200 and it is running good. I ride in CT across the sound from you so our set-ups should be similar. My lows are at 3/4 and highs at 1 3/4..

  8. #8
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    Quote Originally Posted by beerdart View Post
    Check your pop-off you may have a leaky NS. I have a similar set-up on my 1200 and it is running good. I ride in CT across the sound from you so our set-ups should be similar. My lows are at 3/4 and highs at 1 3/4..

    Maybe ill just ride my ski over there and have you take a look at it .

    So i will do a search for a popoff tester to find out if you can make one or where i should get one....

    Then what should my popoff pressure be and what exactly does this measure and do in terms of performance.

    Also, do you know if running these mods w/o a high performance head is ok?

    thanks!

  9. #9
    Moderator beerdart's Avatar
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    Pop-off should be around 43 psi. I use and old beer keg pump.. You can use a bicycle pump or compressor with a regulator. You are fine with the stock head. I ran the stock one last year and was running 71 @ 7050..
    Attached Files Attached Files

  10. #10
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    Quote Originally Posted by beerdart View Post
    Pop-off should be around 43 psi. I use and old beer keg pump.. You can use a bicycle pump or compressor with a regulator. You are fine with the stock head. I ran the stock one last year and was running 71 @ 7050..

    So at 71mph what mods did you have different then me? especially what prop and what pitch?

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