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  1. #21
    Yamaha artisan Cutlass's Avatar
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    Quote Originally Posted by 420kushking View Post
    Took the ski out and everything worked out great. Ran perfect. The only issue was Some hesitation though after long wot, getting off it and right back on it. Im thinking of doubling up bn 34/107 skinny check valve? Any other suggestions? Also whats a good idle rpm, its a bit more shaky it seems, and a bit rich on wot.
    Yep, double up that 34/107 check valve, I did that too.
    Did you end up doing the drilled returns mod? Its a good one to add some more reliability to the fuel system.
    Set the idle in the water to 1200 to 1300 rpm. You have to use an aftermarket tach to actually do that. The 65U motor is shaky beast so it'll never be perfectly smooth at idle.
    If its rich up at WOT, the try running the high speed screw in 1/8 to 1/4 turn. How many turns out are the highs set at now?


  2. #22
    Quote Originally Posted by Cutlass View Post
    Quote Originally Posted by 420kushking View Post
    Took the ski out and everything worked out great. Ran perfect. The only issue was Some hesitation though after long wot, getting off it and right back on it. Im thinking of doubling up bn 34/107 skinny check valve? Any other suggestions? Also whats a good idle rpm, its a bit more shaky it seems, and a bit rich on wot.
    Yep, double up that 34/107 check valve, I did that too.
    Did you end up doing the drilled returns mod? Its a good one to add some more reliability to the fuel system.
    Set the idle in the water to 1200 to 1300 rpm. You have to use an aftermarket tach to actually do that. The 65U motor is shaky beast so it'll never be perfectly smooth at idle.
    If its rich up at WOT, the try running the high speed screw in 1/8 to 1/4 turn. How many turns out are the highs set at now?
    I followed your settings in your previous posts. I drilled the carbs and put a 105 main tapped into a T fitting on the return line credit to osidebill.
    Ill have to order some of those check valves but overall its running 100 % better. I have no gauges and would like a temp gauge, digital or
    Analog whichever....any suggestions...already have a tach by works connections.

  3. #23
    Yamaha artisan Cutlass's Avatar
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    If you still have the old check valves, you can use those. Thats what I did. I don't have a suggestion on a temp gauge. In fact I can't remember ever reading about someone putting a temp gauge on a PWC. Only gauges I've used are a fuel pressure gauge, a tach, and handheld GPS for an accurate speed reading.

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  5. #24
    Went to the lake yesterday, same problems. Bog at wide open, then after it starts to bog wot, bogging gets worse and is noticeable throughout the entire range of throttle. If i let it sit, off, then start to ride it works perfect for ten mins or so, then back to bog. Im starting to wonder if it will ever run right. Feels like its not getting fuel, like after its warm it runs like shit. Overheating maybe? I dont know. Im checking all the coolant lines tomorrow, ill pull the carb rack tomorrow, compression test tonight before i pull the carb rack....open to suggestions

  6. #25

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    97 gp 1200 jetting help

    What type of bog? Falling on its face and dies? Or it hesitates and takes a sec or two to clear out then goes? Or only getting about 1/2 to 3/4 of max rpm?

  7. #26
    Quote Originally Posted by akjose View Post
    What type of bog? Falling on its face and dies? Or it hesitates and takes a sec or two to clear out then goes? Or only getting about 1/2 to 3/4 of max rpm?
    Ok, it seems like ill start the ski fresh from off the trailer, ride around for about a half an hour, maybe an hour... then ill start to get a slight bog, where i mash the throttle and i can hear and feel it stumbling, lack of power and you can just feel it and hear it so i stay off it, it only seems like its after about 3/4 throttle at first.... then since it starts doing that, I head back toward the dock or the beach, using about half throttle or less, it runs pretty smooth, then after doing that for a while... it starts to bog at everything after 1/4 throttle...
    When I let it rest for a while, sometimes even just a few minutes, it will take off at full throttle running properly, then quickly start to bog after another 5-10 mins of riding. I just changed the needles and seats to fresh ones, 1.5's 115 gram springs. tested popoff at 55psi. I also changed out the pilot jets to 100 and the mains to 135s. Cleaned the fuel filters in the carbs. I took it to oceanside where the water is cooler and it ran great, im thinking it might be overheating... tested the compression, Mag 130, middle 132, pto 130 psi. Im going to take off the carbs again and see if the check valves are still in tact.

  8. #27

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    97 gp 1200 jetting help

    Just a thought, have you checked your crank seals? Maybe something is opening up and leaking under heat.

    Since your concerned about overheating, how are your water lines run? Could you take a pic? Are you running a jetworks valve, if so what RPM is it opening?

  9. #28
    What's an easy way to check the crank seals? Also I will get a photo of the coolant lines, the only thing I could think it would be is heat soak bit I didn't think about the crank seals. No jetworks valve, the ski is practically stock engine wise. FA, tdr waterbox and premix

  10. #29
    Yamaha artisan Cutlass's Avatar
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    To check the crank seals you need to do a Engine Pressure Test. If the engine doesn't hold pressure, then it could be a little tricky to track down the leak source with the engine in the ski. Read through these threads for ideas:


    Pressure Testing Two Stroke Engines

    GP1200 65U pressure test
    pressure Testing a 65U SUV
    Pressure Testing

  11. #30
    Quote Originally Posted by Cutlass View Post
    To check the crank seals you need to do a Engine Pressure Test. If the engine doesn't hold pressure, then it could be a little tricky to track down the leak source with the engine in the ski. Read through these threads for ideas:


    Pressure Testing Two Stroke Engines

    GP1200 65U pressure test
    pressure Testing a 65U SUV
    Pressure Testing
    Hey thanks for the info, it looks like if i want to pressure test it, might be easier just to pull the motor out.... It does not look easy and it looks like ill have to buy some metal plate and gasket material... PITA.. Im not shy to pulling the engine out though. I have pulled it before. Its pretty light i can lift it myself so if I have to I will pull it. I still need to take another look at the carbs to make sure nothing got clogged in there, and I need to look at the fuel lines because they could have gotten mixed up when I replaced the fuel sender unit. Breaking down the carbs right now.

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