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  1. #1

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    How to get your 1300 to 80?

    I just hit a little over 77 gps today. But I understand that some on the board are running 80. Any suggestions on gaining 3 mph? For instance, with the keyway is additional porting necessary?


  2. #2
    Well sounds like you need some type of handling package.

  3. #3
    Mik72e's Avatar
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    Go see Lowell

  4. #4
    philip_gpr's Avatar
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    First I would suggest you see what HP your motor is making.

    what impeller pitch do you have?

    RPMs?

    You can compare your numbers to the numbers found in this thread. This way you know if you are down on HP compared to everyone else or if you are the same.

    http://www.greenhulk.net/forums/showthread.php?t=13192

    Next look at your handling components.

    What rideplate? (any mods?)

    What intake grate?

    What pump nozzle? (87 mm or 85 mm)

    What compression? What Squish?

    here are instructions for measuring the squish

    http://www.2-stroke-porting.com/squish.htm

    You are already running as strong as most of the package skis so getting a package won't help.
    Besides you can read about most things that work from the package in my Riva thread. You might also find some new ideas there as well. (for example have you done anything to get more air to the motor?

    http://rivaforums.com/eve/forums/a/t...4/m/2571066093

    The most important top speed item is the rideplate and the rideplate mounting angle. Have you tried different mounting positions or did you just mount it and go.

    What I do is machine both the front and rear mounts a little extra so then I can fine tune the rideplate angle and position.

    With Advent and Macboost both coming out with replacement EFI and ignitions for the 1300 I would think in 2007 we will see more skis above 80 because they will add one of these controllers and this potentially will allow you to more easily up the displacement to something like 1390.
    Last edited by philip_gpr; 10-30-2006 at 09:04 AM.

  5. #5
    Happily Self-Employed WFO's Avatar
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    Quote Originally Posted by Purple Haze View Post
    I just hit a little over 77 gps today. But I understand that some on the board are running 80. Any suggestions on gaining 3 mph? For instance, with the keyway is additional porting necessary?
    Call TJ, he has some updated porting specs.

    My non-ported EFI was running 77+ with Fercho's package.

    All you need is some fine tuning. Call me and we can go over your combo and some new stuff coming out.

  6. #6
    All hail the Chief! fullboogie's Avatar
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    Getting into the 76-78 range is relatively easy by throwing money at it. Getting that last 2 to 3 mph is all about the details, which you will have to handle.

  7. #7

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    Thanks for the replies. WFO could you send me your phone number?
    Phillip GPR - thanks for the great response. The rideplate was one from Jim that is smooth as glass - using two washers in front. Trim tabs are R&Ds that Jim cut and mirrored finished. Stock sponsons. I think the compression is at 145? Switched to the 800 plate. 87 nozzle. Impeller is a dynafly
    15x26 1/4.

    Any other thoughts?

  8. #8
    Moderator RX951's Avatar
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    Quote Originally Posted by Purple Haze View Post
    - using two washers in front. ny other thoughts?

    How thick are those washers? Also, make sure with those two washers in place, the bottom of the rideplate should not hang past the pumpshoe/hull line. There should be a slight step up from the pump shoe up to the ride plate.

    Also foremost, make sure your pump shoe is not hanging down either. The pump shoe should be recessed in the hull and not protrude below the hull line.

    what RPMs are you turning?

    Fullboogie is right, there are some small details now that you need to work on.

    WFO will hook you up, he's also one of our EFI GURU's

  9. #9
    Mongoose's Avatar
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    I would get an accurate rpm reading first.
    You may have most of what you want in the prop, but you need an accurate rpm reading to see if it can be bent to suit.

  10. #10
    philip_gpr's Avatar
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    everything looks good

    as others have suggested an accurate rpm number would help

    get with WFO maybe he can help get you some more HP

    if you haven't already try different shimms at the front of the plate - on my Riva post I listed what the step was from my shoe up to the plate (but every ski is different)

    measure the squish on all 3 cylinders - if it is .050 inch or more you could remove the head gasket split it in 2 and reinstall head with only 1 layer of the gasket

    with that 26 pitch impeller I bet your rpms are on the low side - you might try a 2nd impeller that is pitched at 14/24 (get a 2nd, don't repitch the one you have because it is running pretty [email protected] good) - but my experience is the steeper the impeller you can pull the better - for example my ski is faster at 7,000 rpm with a steeper impeller than at 7200 with a less steep impeller ( so much for the common idea you should run the motor at 7200 )
    Last edited by philip_gpr; 10-30-2006 at 07:34 PM.

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