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  1. #1
    Tony's Avatar
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    SLT780 No power= big trouble.

    Background: I bought the ski 3 weeks ago (MFD not working). First two times out it ran excellent. The last ride of the second trip it wouldn't start. Had been riding for 6+ hours so I figured I was out of gas. Added gas and it finally started but had NO power. loaded up and went home.

    I posted my problem and I/we decided I needed new fuel lines, filters, shut off, etc. I replaced everything but the pump and even got the MFD working with a fuse. Ran good on trailer (2800-2900 rpms) and couldn't wait to go to the lake again.

    Today: I start it up today at the ramp and all seems good. I let it warm up for about 2 minutes. When I go to take off and get nothing...No power. Since the MFD is working this time I can see I'm only getting about 4000 rpms and the gas gauge reads empty on a full tank. I figure it's in limp mode and ohm the sender (tests bad). I put a 33 ohm resistor in line and the MFD reads full so I figure I'm good to go. No such luck, same problem.

    Back at home I run it for 5 minutes and get dome temps of Mag 240, Cen 102, Pto 100. I pull the plugs and they are just a little wet, the Mag being the wettest.

    Compression test shows trouble! Mag 85psi Cen 115psi Pto 115psi. I add a little oil to the Mag and get 115 psi.

    Looks like my first ski experience is going south quick!

    So what to do? I wanted it to last the season and then Mod it out over the off season (thanks to you guys getting me hooked).

    What do you think caused this? How likely is it I can get away with maybe rings and honing and carb rebuild/tuning for now and then blow my life savings on go fast goodies after the season.

    Decisions, decisions,decisions


  2. #2
    Connecticut CrazyA's Avatar
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    When you loaded up the fuel tank, how was your oil level??


    .

  3. #3
    Moderator beerdart's Avatar
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    Tony Some pics of the pistons would tell the story.

  4. #4
    Tony's Avatar
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    Quote Originally Posted by CrazyA View Post
    When you loaded up the fuel tank, how was your oil level??


    .
    Oil tank was full. Last weekend I used one tank of fuel and 1/2 tank of oil. I filled both tanks before heading out today.

    Quote Originally Posted by beerdart View Post
    Tony Some pics of the pistons would tell the story.
    Dead batteries in a crappy camera. But I'll get some pictures of the piston tops tomorrow. I don't know if I'll have time to remove the jugs tomorrow because the wife wants to take the boat out , but maybe my camera can get some pics of the cylinder walls with the pistons at BDC.

    I forgot to mention that when I hit the throttle a few quick times with the F/A off I see a mist of fuel out the top of the center carb, less out of the mag carb and little to none on the Pto carb. Is this bad reeds?
    Last edited by Tony; 06-09-2007 at 07:15 PM. Reason: more details

  5. #5
    damn I run two full tanks of gas through our 780 before I am half a tank in the oil window..

  6. #6
    Tony's Avatar
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    Quote Originally Posted by gvnitup View Post
    damn I run two full tanks of gas through our 780 before I am half a tank in the oil window..
    I should have said " I ran a tank of gas last weekend and the oil was down to half.....I ran on the same tank of oil the previous weekend also.

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