Results 1 to 7 of 7
  1. #1

    New to the Waverunner scene. Problem with carbs.

    I am new to the pwc scene. I picked up a GP1200 with only 72 hrs. on it, it's the red/black/white color scheme of 1997 but the title says it's a 1998. I have a snowmobile and a motorcycle but this tuning of a Waverunner is a chore. I read forum upon forum and tried to make the apprpriate decisions for set-up. I had bounced back/forth about switching to pre-mix and I just ended up buying new Tygon lines/clamps and sticking with the injection. I know there are bounds of carb posts all over the internet but can someone walk me through a stock carb tune? I replaced the oil lines and thought to go through the low speed side needles. I took out, cleaned and replaced the o-rings in thoughts to start "fresh." Now I can't get it to idle right and I've had "runoff" twice. When I do the start-up, do I need to have the complete air intake assembly on? WIll it affect the ratio that much? The service manual says for the LSS to be 1.25 turns out for #1,2 and 1.125 turns for #3 but I see other sources saying only 1 turn out across the board. That runoff happens because of being lean, would that be because I only have the needles 1 turn out or the top silencer cover off? The thing ran great until I changed the oil lines and o-rings on the LSS. Can someone please tell me if the entire intake silencer has to be in place and what I should do with the LSS/HSS(even though I didn't touch those).

    Any help would be greatly appreciated. I really don't want to have to take this to dealer/shop for something that could/seems like it should be an easy fix that I'm just missing. Could these issues be because I don't have in water? I'm trying to test on hose.

    Thank you,


  2. #2
    I am not completely sure about this as I only know my ski (gp1200r). But the stock air assembly is quite restrictive. If you have nothing on the intake side of the carbs it's very likely you are getting entirely too much air in your mixture. I would put the assembly back on and tune from there. Nothing worse than running lean.

    Have the carbs been cleaned or rebuilt recently? Might wanna look into that. If everything is stock on the ski you should be in the realm of 1 turn out on the lows.

  3. #3
    Julian's Avatar
    Join Date
    Oct 2011
    Groningen, Groningen, Netherlands
    You tune your carbs to match your engine setup ( tuning )

    Oil pump can be reliable on stock setup, ( lines and clamps in good condition )

    If you tune up your engine even a little----> premix!

    More power, more fuel, more stress, but no more oil if you use the stock oilpump, that's the main issue.

  4. #4
    Yamaha artisan Cutlass's Avatar
    Join Date
    Oct 2010
    Madison, WI, USA
    I would say, put the adjuster screws to the stock setting, put the air cleaner/silencer back on and together and put the GP in the water. You could just back the trailer into the water, leave the front winch strap hooked up and run the ski on the trailer in the water to see how it does. When you're happy with the idle, then take it out for a spin. Hopefully those oil lines are full of oil and you bled the air out of them, right?

  5. #5

    Yes, the oil system was bled before I tried starting up. That's part of the reason why I had the top cover off, to make sure/verify that oil was coming into each carb. Everything on the oil side is solid. I'm going to set the LSS per the 1.25/1.125 turns, put the complete silencer back on and see what I get. I know there can be a bunch of other causes but this thing ran perfectly before I touched the oil lines/o-rings on LSS. We'll see what happens though. Thanks for the input everyone.

  6. #6
    Am I right in my thought process of thinking that even if the carb(s) are running lean on fuel, since I still have oil injection, that the cylinders will still be kept lubricated but I'll just have running issues/fuel problems/probably foul plugs until I figure out the lean issue but won't blow the engine like if I was using pre-mix?

  7. #7
    Yamaha artisan Cutlass's Avatar
    Join Date
    Oct 2010
    Madison, WI, USA
    No. no matter how much oil is in the engine, it can still have a lean meltdown. Most lean meltdowns will happen at WOT so avoid prolonged WOT (less then a few seconds) if you detect a lean WOT. You're pretty safe under WOT in most cases but I'd still be careful. If it was fine before, then I think the problem is just having the air cleaner off and thats affecting the signal to the carbs.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. New to the site. Problems with a 99 SUV
    By 96roadking in forum Yamaha Open Discussion
    Replies: 2
    Last Post: 06-26-2013, 08:58 PM
  2. new to the sc scene does this all look normal?
    By bigo in forum 4-Tec Performance
    Replies: 17
    Last Post: 05-31-2011, 07:45 AM
  3. Replies: 14
    Last Post: 07-13-2010, 06:17 PM
  4. New to the sport and have an issue with a 99 GP800X
    By StuntCockRacing in forum Yamaha Old School Skis
    Replies: 6
    Last Post: 08-20-2008, 09:13 PM
  5. New to the sport and have an issue with a 99 GP800X
    By StuntCockRacing in forum Yamaha PWC Performance (2-stroke)
    Replies: 3
    Last Post: 08-17-2008, 11:40 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts