Hanging on the Bars: What's going on here?
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  1. #1
    PWCToday Guru E350's Avatar
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    Hanging on the Bars: What's going on here?

    We have three functioning vintage jet skis. A '94 SN Super Jet, a '88 650cc X2, and a '93 550sx. When I ride the 550sx (189 psi both cylinders, 1 gal. 110 leaded race gas to 4 gals. premium, 32:1 Klotz Jet Craft oil) at wide open throttle it seems fast to me.

    But recently I started hanging back on the bars with what seems like little or no weight on my feet. And the ski stops slapping the chop as much and - incredibly - it accelerates faster, to scary fast.

    What is going on here? The engine is not increasing rpm, I am pretty sure of that. Is the top loader intake grate cavitating less? grabbing more water? is the hull flatter more nose down and planing more slippery?

    The best picture of the riding posture I am talking about is shown in this picture I snipped from youtube:

    Camp Far West 7-16-17 Vintage Ski Race.JPG

    What is going on?
    Last edited by E350; 10-03-2018 at 12:39 AM.
    Learning Slowly...

  2. #2
    PWCToday.com Is My Home Away From Home garrcass's Avatar
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    Re: Hanging on the Bars: What's going on here?

    Quote Originally Posted by E350 View Post
    We have three functioning vintage jet skis. A '94 SN Super Jet, a '88 650cc X2, and a '93 550sx. When I ride the 550sx (189 psi both cylinders, 1 gal. 110 leaded race gas to 4 gals. premium, 32:1 Klotz Jet Craft oil) at wide open throttle it seems fast to me.

    But recently I started hanging back on the bars with what seems like little or no weight on my feet. And the ski stops slapping the chop as much and - incredibly - it accelerates faster, to scary fast.

    What is going on here? The engine is not increasing rpm, I am pretty sure of that. Is the top loader intake grate cavitating less? grabbing more water? is the hull flatter more nose down and planing more slippery?

    The best picture of the riding posture I am talking about is shown in this picture I snipped from youtube:

    Camp Far West 7-16-17 Vintage Ski Race.JPG

    What is going on?
    The front of the hull is out of water and for the most part only the rear of the hull and the intake are in the water less surface area = less resistance = faster... A top loader should not cavitate at all unless your in chop or turning the purpose of them is to essentially keep shoveling water to the pump and keep it loaded.

    A lot of race starts guys seem to be in that position nobody is poised over the bars in attack mode unless there is a short start area with a turn buoy close

    Thats a pretty deep squat though a rough water day and it might be hard to hold on to that much of a squat..

    There is a decent amount of race fotage on
    You tube

    Badass holeshot
    Last edited by garrcass; 10-03-2018 at 01:50 AM.
    ( Girlfrends are cheap X2,s are expensive )

  3. #3
    PWCToday Guru E350's Avatar
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    Re: Hanging on the Bars: What's going on here?

    Thanks garrcass !

    (I can't get enough of your icon...)

    So the genesis of this thread is that I thought I was bada$$ going straight, WOT, through chop. Then I dropped back and hung back on the bars with arms outstretched and let my feet go soft and light and WTH? I accelerated even more even though the engine rpm did not increase !!!

    So, I see that guy in the 2017 Camp Far West 550 race video and he is in the same posture and in the lead and then it hits me that there is a whole realm of "go fast technique" which has nothing to do with engine rpm, pump, etc. but has everything to do with hull attitude.

    My preliminary conclusion is: Weight in the tray slows you down because it creates drag. Arms outstretched, butt back, soft and weightless feet lets the nose come down, the tray to come up, and the ski to level out on a slippery flat plane.

    Look at the different ski attitudes of both first place and second place skiers in the 2017 Camp Far West video snip above. Full video is here:

    https://www.youtube.com/watch?time_c...;v=_Z-IUlU2mmc

    This technique is contrary to the current freestyle mod of cutting the pole shorter to enable the rider to put more body weight on the nose of the ski to push the nose down. Rather, it seems to me at this point in my learning that the stock longer pole lets the skier get farther back to let the ski lie flatter to plane with less engine/pump effort.

    So, I went to youtube like you said and watched the 1991 Pro World Finals for 550:



    Holy crap, those guys are super low for their turns, almost laying down, keeping one foot in the tray with the other foot hanging out dragging the water on the inside of the turn. And I am pretty sure they are WOT for the entire race...

    Pretty humbling...

    I would like to learn more about go fast technique which has nothing to do with engine or pump mods.
    Last edited by E350; 10-03-2018 at 11:47 AM.
    Learning Slowly...

  4. #4

    Re: Hanging on the Bars: What's going on here?

    Nice video. My favorite moment is at 2:06

  5. #5
    PWCToday Guru E350's Avatar
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    Re: Hanging on the Bars: What's going on here?

    2strokesmoke: 2:06 in the Camp Far West video is a racer falling over after the log jump.

    2:06 in the 1991 Pro Mod Race is Chris Fischetti buried in whitewater making a buoy turn followed closely by Victor Sheldon.

    Everyone needs to start somewhere, but there is great contrast between the two races.

    I know you know how to ride. Your avatar shows it.

    So, any suggestions?

    Or should I just continue with my trial and mostly error?
    Learning Slowly...

  6. #6
    PWCToday.com Is My Home Away From Home Myself's Avatar
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    Re: Hanging on the Bars: What's going on here?

    Look at your pic in post #1. The closest in "hangin off the rear" mode, and second standing sort of crouched. Now look at the whitewater "wash" coming out from underneath the hull and where that wash is. Farther off the back brings the nose up but....nose up and fully planed out at speed leaves nothing more than pump in the water. Best for top speed runs. The 550 hulls start to "hunt" real bad at about 40mph. I've not been any faster on a 550 hull but will soon after I complete my swap.
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  7. #7
    PWCToday Guru E350's Avatar
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    Re: Hanging on the Bars: What's going on here?

    Myself: You are correct. I was incorrect. I see now from the shadow and the hull wash on boat in first place position that the surface area of the hull in the water is in fact more aft. And that the nose is higher not flatter. However, that boat is indisputably faster. So I guess it is having nothing but pump push the boat forward which is adding that acceleration? What a kick! And a goal to be able to control the hull at that speed with only the pump in the water.

    I know about the hunting on the 550. Let's see if it hunts less with less hull in the water!

    But I prefer it to the Square Nose "wiggle" which our '94 SN Super Jet does at WOT.
    Last edited by E350; 10-03-2018 at 04:29 PM.
    Learning Slowly...

  8. #8

    Re: Hanging on the Bars: What's going on here?

    I have a had few oh sh*t moments on the ol 550. Just keep riding and do what works for you. Love watching the good old days videos too.

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