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  1. #41
    Still sounds lean. Did you turn your adjusters way out and see if that helped? I am praying for you that it is not an air leak like it was for me. My ski behavior was similar.

    Did you check your plugs? You don't have access to a borescope where you could get a look at the top of the pistons? I'm fairly certain you're lean but it's better to verify than guess.

    As for your water leak, you've essentially got two potential sources. A leaking exhaust joint or an engine water line. Maybe you forgot to reconnect one and it's dumping water in the hull when the engine is running?

  2. #42
    Quote Originally Posted by 12ozcurls View Post
    Ok. One thousand adjustments later. Ski runs great on the trailer. Put it in the water and it wonít rev past 2500 or it dies. Hollow bog sound unto the point it dies and only take about two seconds of a throttle squeeze past 2500 rpm. All new minkuni parts. 1.2 n/s. Stock jets. Pop off was at 62 on all three carbs. Someone messaged me and said it should be closer to 40. I adjusted springs and got a new pop off of 38 but same thing. Runs great on trailer but stuck at 2500 rpm in the water. I have read several threads now and I total confused at what stock pop off should be on this ski with it being all stock and 1.2 n/s. I put in boyesen power reeds but nothing more. Any suggestions? Iíve seen pop off psi posted online anywhere from 40 to 85.

    no exhaust leak (smoke) in engine compartment. I have crimped all primer lines. I do seem to be taking on water somewhere in the hull. Even while in the water for 30min trying to test it on the trailer at the ramp I take on enough water to drain when I pull the plugs. Could there be some kind of water box leak causing all this?
    ?? spring weight and pop-off for this stock ski?

  3. #43
    Quote Originally Posted by 12ozcurls View Post
    ?? spring weight and pop-off for this stock ski?
    All my experience is with the power valve motors. Can you find the service manual somewhere (NOT owners manual)? All the specs are in there. Bottom line is a specified needle size with a specified spring weight yields a specified pop off pressure. If you can find those two specs, pop off should be easy to figure out.

  4. #44
    Quote Originally Posted by LipschitzWrath View Post
    All my experience is with the power valve motors. Can you find the service manual somewhere (NOT owners manual)? All the specs are in there. Bottom line is a specified needle size with a specified spring weight yields a specified pop off pressure. If you can find those two specs, pop off should be easy to figure out.
    i have the shop manual. Doesn’t talk about carb internals really. Certainly no pop-off specs. Minkuni manual I also have but everything starts at 1.5 n/s and is not ski specific. Need direction from someone with gp1200 experience. Thanks.

  5. #45
    steve45's Avatar
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    There are a number of settings based upon needle size, etc.

    Perhaps this will help:

    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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  6. #46
    Thanks Steve45. I have that chart but it doesn’t cover 1.2 which was stock in the 98gp1200. The pop-off is what I’m having trouole
    with. Everyone give a different stock pop-off for the ski stock. Stock air box.

  7. #47
    Quote Originally Posted by 12ozcurls View Post
    Thanks Steve45. I have that chart but it doesnít cover 1.2 which was stock in the 98gp1200. The pop-off is what Iím having trouole
    with. Everyone give a different stock pop-off for the ski stock. Stock air box.
    You know what needle came stock do you know which spring?

    If you know those two, we can tell you what your pop off should be.


  8. #48
    I know 1.2 n/s but I don’t see the spring weight listed anywhere. I’m leaning towards 95gr springs but then the pop off is up over 60 which several people to me is too high. Maybe they’re wrong. It’s not on the shopmanual nor model specific in the Mikuni manual.

  9. #49
    Don't be so sure that 60 is too high.

    Look at what a 1.2 and 115g spring gives you - that's what comes stock on GP1200R's with their super restrictive intake tract.

    Do you have the original springs?

  10. #50
    Can’t tel if they are stock or not. Trying to order stock weight springs.

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