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  1. #1
    la90043's Avatar
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    Jet sizes incorrect?

    i have a 1996 slt 780. engine number is EC780PWE0503242.

    IT HAS CURRENTLY MAIN JET SIZE 107.5 ON ALL 3 CARBS AND 72.5 SLOW JETS ON ALL THREE TOO.

    ARE THESE THE CORRECT JETS PER THE SERVICE MANUAL AND THIS SLT 780 HUH?

    IM CURRENTLY SETTING THE HIGH AND LOW SPEED ADJUSTERS AT LOW=
    1 3/8 AND HIGHS ARE AT M=1 1/8 C=7/8 AND PTO=1 1/4.

    IS THIS CORRECT? DO I HAVE MAIN AND SLOW JET OF A SL780 AND NOT OF A SLT780 HUH?

    OR THIS IS CORRECT AND I SHOULD ADJUST THE LOW AND HIGH ADJUSTERS TO LOW=5/8 AND M=3/4 C=3/4 PTO=1

    SOMETHING IS FISHY AROUND HERE.


  2. #2
    la90043's Avatar
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    bumpity bump

    bumpity bump

  3. #3
    SPEED KILLS, BUT YOU GET THERE QUICKER Keddano's Avatar
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    Seems to be the jetting for a '96 SL not the SLT.
    The SLT should be #110 highs, m=1 1/8, c=7/8, pto=1 1/4
    #67.5 lows @1 3/8 turns

    Seems that there was some difference in the transition holes in the carbs,(See Note at bottom) Guess you would have to figure what carbs are there for the right jetting. But it also seems your engine # does match what they are showing.
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  4. #4
    la90043's Avatar
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    ordered

    Hmm. just as i thought. weird though. them carbs always had a tuning issue i could not fix. that is the corporate i guess. maybe previous owner ran the boat at way higher elevations than close or at sea level.


    ordered 110's and 67.5's this morning. i'll have them this afternoon!

    mikuni distributor nearby. (Anaheim Ca.) i ordered them through a pwc/offroad dealership also in Anaheim for super duper fast delivery.

  5. #5
    SPEED KILLS, BUT YOU GET THERE QUICKER Keddano's Avatar
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    I might try just changing the highs first. And leave the bigger lows,see how it runs,better fat then lean.

  6. #6
    Plrs X45's Avatar
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    Quote Originally Posted by Keddano View Post
    I might try just changing the highs first. And leave the bigger lows,see how it runs,better fat then lean.
    I also have an SLT 780. Do I turn the screws in or out to richen it? the low screws are where? The high screws?

    Thanks.

  7. #7
    la90043's Avatar
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    take the flame arrestor off. look at each carburetor. one side of the carb near the top is the high speed screw. on the other side of the carb near the bottom is the low speed screw. turn screw out to richen. turn screw in to lean it. read your piston wash first before moving the high spped screw.

  8. #8
    la90043's Avatar
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    each screw will probably have a blue or black cap on it. you can pull them off with a small screw driver to correctly adjust the high and low speed adjuster screws.


    Quote Originally Posted by la90043 View Post
    take the flame arrestor off. look at each carburetor. one side of the carb near the top is the high speed screw. on the other side of the carb near the bottom is the low speed screw. turn screw out to richen. turn screw in to lean it. read your piston wash first before moving the high spped screw.

  9. #9
    la90043's Avatar
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    got the 110's and 67.5's in my hands! same day delivery for the jets. GREAT!

    why would the previous owner run rich on the low end and lean on the high end

  10. #10
    BBCaprice's Avatar
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    Man you really got to read piston wash to know for sure. Wash light at the least or borescope is the best.

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