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  1. #1
    skigolfnut's Avatar
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    Tuning red top carbs

    I want to get better performance on my 785 pro, I was thinking of doing the Randy tuning tips for girls, and do I look at my piston wash?
    I am pulling strong off the line, but in race trim I am only getting 7500-7600 rpm's
    Shoud I adjust the linkage so they all go wide open?
    Then start from there with the tuning tips?

    thanks,


  2. #2
    bowsniper's Avatar
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    [QUOTE=skigolfnut;1701165]I want to get better performance on my 785 pro, I was thinking of doing the Randy tuning tips for girls, and do I look at my piston wash?
    I am pulling strong off the line, but in race trim I am only getting 7500-7600 rpm's
    Shoud I adjust the linkage so they all go wide open?

    Your not wide open now? Of course you should.. it should already be like that.. What kind of wash are you getting now on the pistons? Can you take the head off or look down the bores and see what things look like? I dont know if that worx grate is grabbing more water than a R and D intake grate you were talking about earlier..

    Stator in good shape? impellor clearence within spec? not over 20 thous? even that is huge.. more like 2 -4 thous would be much better.. Valves opening all the way? You can check the valves movement by energizing the valve motor for a second both directions.

    I have the redtops also.. I heard they are very sensitive to humidity and temperature.. aka..pita to tune..lol although, out of the hole on mine seems to be right on. the highs?.. still working on that end with the wash..
    same boat..

  3. #3
    skigolfnut's Avatar
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    When it is hitting wide open on the PTO stop, the other 2 are almost there but not wide open,
    I didnt want to screw up the sync,

    should I tune all three together? how do you tune separate?

    Mine is real good out of the hole, it is arm wrenching on the start, but I would like more top end,
    my next race is not until July, I dont want to muck up anything, I am going to write down were I started at, so I can always go back,
    I will take the head off this weekend, I also have a boroscope,

    thanks,

  4. #4
    Polarisracer166's Avatar
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    Before you start any tuning you need to get all three carbs in sync. This can be done on the boat starting with the first carb that is closest to the throttle wheel. You should create a build sheet of all components on the ski, (Prop Pitch, Pump Stator, Reeds, Compression, Fuel and Mixture, current jetting)

    1) Make sure all three butterflies are opening the same based off the first one.
    2) Read Randy’s tuning tips and following them 100%
    For testing I always adjust the nosle to +2 using a degree wheel and install a [email protected] intake grate with a 4 degree wedge.

    3) Check your current piston wash before you start messing with jetting.
    4) Read Randy stunning tips again..

    Redtop carbs are the same to tune as a standard Stock 785 44MM carb. What makes them more difficult that if they have a 2 hole bleed system (1997)

    I would use this jetting as it will yield 7900-7950 with a 12/17 impeller
    (As long as no other issues are going on )

    No Choke Plates
    OEM Throttle Plates
    Low Speed jetting Mag 125 / Cent 125/ PTO 125 – (1 turn out)
    High Speed jetting Mag 125 / Cent 125/ PTO 125 – (.5 turn out)
    2.3 Needed and Seat with a 95 gram spring

    I would call Lugs to see if he has any carbs for sale.. Take those RedTops and give them to your worst enemy. They will not produce real acceleration…

    I just gave away 3 sets…

  5. #5
    skigolfnut's Avatar
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    thanks,

    I will start this weekend,

  6. #6
    PolarisRacer-

    Is your jetting reccommendation above for redtops or stock '98+ carbs? If it is for redtops, what do you suggest for stock carbs? Thanks!

  7. #7
    skigolfnut's Avatar
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    From what I gathered it is the same for both,

  8. #8
    skigolfnut's Avatar
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    I just checked my highs and low jets, they were all turned out 1-1/4 turn out except my center high, it was at 1 turn,
    Geez it is a was miracle I was even getting around the course.
    I did notice that it has the V force reed valve system, vavles are opening all the way, I am going to take the worx grate off and put the r & d one one, I dialed it the auto drop nozzle, and adjusted the pull dump nozzle for the hole shot,
    now I just need to get the carbs dialed in to run some peak rpm's

  9. #9

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    Quote Originally Posted by skigolfnut View Post
    I just checked my highs and low jets, they were all turned out 1-1/4 turn out except my center high, it was at 1 turn,
    Geez it is a was miracle I was even getting around the course.
    I did notice that it has the V force reed valve system, vavles are opening all the way, I am going to take the worx grate off and put the r & d one one, I dialed it the auto drop nozzle, and adjusted the pull dump nozzle for the hole shot,
    now I just need to get the carbs dialed in to run some peak rpm's
    you have to check your wash pattern ,jetting specs are different in every part of the country what works in one part of the country can be way different then somewhere else and fuel types matter also

  10. #10
    skigolfnut's Avatar
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    I will pull the head this weekend, and check the wash and take some pictures,
    I am using VP MS103 fuel with a 40/1 royal purple mix,

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