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  1. #1

    Converting to pre-mix on 2001 xlt 1200. Do carbs need to be retuned?

    As title states, would I have to adjust carbs?
    I would rather keep the oil injection intact, however, I'ved had oil in bottom of hull last couple years. I can't seem to pinpoint the leak. All 3 cylinders are 120 psi.
    Please let me know regarding carbs, or if you've experienced oil in hull, and what you've discovered.
    Thanks in advance,


  2. #2
    I wanna go FAAAAASTer!! CDW78's Avatar
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    If you remove the pump and go to premix, no you don't have to change anything with the carbs. a lot of people prefer the premixed simply for the peace of mind and safety. You can keep the oil injection just make sure your pump is working correctly and if you've never replaced the oil lines, especially if you have a leak, it would be a good time to do so as well as replace the zip ties with actual clamps. Having oil in the hull indicates a likely leak somewhere. I double check the tank the hoses and everything just to be safe.

  3. #3
    Thanks for your reply CDW. Trying to adjust those carbs with the pipe on is impossible. I have been unsuccessful in finding this leak for the past year. Will check underneath the carbs with a mirror and fine tooth comb to salvage the oil injection, however, if I cannot find, then premix.

  4. #4
    Have the airbox off, and looks to be plenty of oil pooling in middle and rear carb. All oil lines look to be secure and fastened.
    Any suggestions?

  5. #5
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    Quote Originally Posted by harpo97 View Post
    Thanks for your reply CDW. Trying to adjust those carbs with the pipe on is impossible. I have been unsuccessful in finding this leak for the past year. Will check underneath the carbs with a mirror and fine tooth comb to salvage the oil injection, however, if I cannot find, then premix.
    Not sure if yr ski has a check valve, but my gp1300r was doing the same thing... oil in the hull. Come to find out it was coming out the check valve, dripping down the hose into the hull.

  6. #6
    I have checked any line with oil and no leaks. When I look into the carbs, there is excess oil in the carb throat, as the carbs sit sideways. Decent accumulation of oil in carbs 2 and 3. That's where I'm suspecting the oil is coming from. Good thing is there's plenty of oil getting to the cylinders. Bad thing is too much. As if the oil keeps flowing, in miniscule amounts, after the ski shuts off. The oil in the hull accumulates on the right side hull, underneath the carbs. Any one else have experiences such as this. Thoughts??? Is there an oil mixture screw somewhere? I may just have to live with the excess oil unless I do the inevitable, which would be the premix.

  7. #7
    I wanna go FAAAAASTer!! CDW78's Avatar
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    Have you checked the tank itself ? Likely not the problem, but seems if you've checked everything else. Can you see any oil leaks with it running ? I'd swap out all the lines from the pump to the carbs, replace clamps and see what that does. It couldn't hurt regardless. AS 007 mentioned, could be a check valve if oil is continuously flowing to the carbs.

  8. #8
    Thanks for the suggestions CDW and GPR.
    After some research through this forum, here's a quote from and old thread by Steve45.

    Marvin, I wasn't aware that any of the PWCs used these, but they are in all the 2-stroke boats regardless of engine.

    These valves are referred to as 'check' valves, but they are not check valves. They are 'relief' or 'pop-off' valves. A check valve prevents backflow, while a relief valve allows flow when a predetermined pressure is reached.

    In a Yamaha jet boat, the oil reservoir is mounted above the engines. When the reservoir is full, there is about 2 feet of head (hydrostatic pressure) in the oil system. When a boat is stored for weeks or months, that pressure would cause oil to seep through the oil pump and flood the carbs. This causes heavy smoke and fouled plugs after starting. The relief valves are designed to prevent this seepage. Oil should only flow when the pump increases the pressure above the popoff pressure, opening the valve.

    Also, when the relief valves are in place, a very flexible hose should not be used (i.e. silicone hose or 'surgical rubber' hose). If you were to do this, the hose would flex rather than opening the valve.

    This would make sense since I see oil building up inside of the carbs and that would explain my inclination that the oil is originating from the carbs and coming out of the airbox. I hope.....
    I will order the new release valve's and try to stay with oil injection.

  9. #9

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    If your reeds are worn you could be getting a lot of blowback causing oil to accumulate. Also, if the FA to carb gasket is leaking oil will pour from the carbs.

  10. #10
    Thanks for the info butterbean. I am not ruling anything out. What's the FA?

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