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  1. #1

    Join Date
    Jul 2005
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    Lake Dunlap, Texas
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    Found cause of lost speed

    On November 13, UTClason posted that he had lost two to three MPH in top speed and I chimed in that I was having the same problem, which was RPM was still at 8100 to 8150, but we had both lost some top speed. I was running right at 73MPH before speed drop. Went 1400 miles to visit PPG (they had installed their level one kit in January of this year) to correct my problem. I said I would post the results so here they are. One must remember what was found with mine might not cure all skies with a simular condition. Wear ring was found to have some pits (not in the area where the prop turns/runs, but farther to the rear of this area.
    They were five in number, about one thirty seconed to one sixteenth of and inch deep (sorry I am not a millemeter guy--i am very old--in my seventies--never got into that stuff) and about one half to three quarter of an inch in diameter. This was my orginal stock ring (84 hours on ski).
    Frazier replaced the wear ring upgraded the pump bearing to a larger one--not for speed but for realiability. Tested the ski with me holding the radar gun and Frazier riding and speed back to 72.6 (quite choppy and windy and going into both) Then installed RR ECU--Frazer did a little more magic on the prop---went out next day--speed now 75.2 in same chop and head wind with more acceleration and hole shot and 8350 to 8400 RPM Figure when I get back to my smooth lake might crack 76 MPH. If not--I am quite pleased with its peformance where it is during the tests. Also took my 1999 GTXL for 200 hour service and checkover.


  2. #2

    Join Date
    Jul 2005
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    Lake Dunlap, Texas
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    Another problem--but this one I like. Took my ski out this afternnon here at home after coming back from Florida. Air temp 67 degrees--water temp 78 degrees. After several minutes warm up--nailed it. The proplem is--turning 8450 RPMs. Not good. Already have an 81MM venturi-
    one MM smaller than stock. Fraizer at PPG loaned me an 80MM venturi and I will install it to see if I can bring RPMs below 8400 and maybe pick up a half mile or full MPH. Will keep thread posted as to results.

  3. #3
    Water4fire's Avatar
    Join Date
    May 2005
    Location
    New Braunfels TX.
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    Ray that sounds awesome. I still want to come by and check it out, but am crazy busy.
    Great results. I am jealious.

  4. #4
    EZ Dock of Long Island Shibby1485's Avatar
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    May 2005
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    Long Island, NY
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    nice job!! glad to hear u got things worked out with PPGs help. Definitely be sure to update us with some GPS numbers after you install a smaller nozzle...

    question for a pump expert: ~~ is it better to make venturi diameter smaller little by little to fine tune, or is it better to pitch the prop to change RPMS... there HAS to be a science to this... a point of diminishing returns where you should stop changing the venturi and start playing with the prop or the pump cone and vice versa. There must be a point where you actually LOSE even tho you have perfect rpms but the venturi is smaller and smaller.

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