UMI Racing Intake Grate????

M

Me KawaSki

Location
Melbourne Beach Fla.
I just bought my first stand up (Bone stock 92 750sx) and it porpoises like hell. I am 6'1 and 215lbs, so to most, this is no surprise. I was thinking about changing the ride plate and the intake grate to alleviate the porpoising. Upon closer inspection, I discovered that the intake grate is a UMI Racing grate. I personally have never heard of a UMI intake grate nor can I find ANY information on it. I want to use the ski for riding in the surf.
I need to know:
1) Is this grate a POS?
2) What is this grate designed for......flatwater, chop, etc..
3) Should I keep it or toss it. If toss it, what to get for surf riding and no porpoising?.....besides a sj.......
4) Could this grate be contributing to the porpoising?

Here are some pics of the grate:
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brett

brett

-------------
Location
Ventura,ca
not really. its more about practice. the more you ride, the more you'll learn to change your positioning to stop the porpoising. try putting more weight on your front foot.
 
tightithrash

tightithrash

Zack Bright. I Thrash.
Site Supporter
Location
Oceanside, CA
750sx..........they just porpoise........a longer ride plate would help.....and hull extensions........thats what were doin to my friends.....
 
M

Me KawaSki

Location
Melbourne Beach Fla.
brett said:
not really. its more about practice. the more you ride, the more you'll learn to change your positioning to stop the porpoising. try putting more weight on your front foot.
Click to expand...
I figured that practice will help, but this porpoising seems excessive. I tried leaning forward as far as I can with my feet touching the wall in front, the chinpad buried in my stomach. This helps the porpoising alot, but I shouldnt have to ride like that all the time. I'm not sure if anyone could. As soon as the ski fully planes out, it will start porpoising severely to the point that it starts to suck air when it comes up. WOT only makes it worse and you can go maybe 5 sec before it starts sucking air due to severe porpoising. It seems that with an extended ride-plate, I should be able to ride more comfortably with most my weight towards the back of the ski and be able to get the nose up by actually trying to get all of my weight far back. Seems nice in theory, but who knows. Only practice and expertise will tell!

You know anything about this grate?
I had read one other person's story about their porpoising problem being caused by their intake grate which is why I thought to ask about this UMI Racing one.
 
tipafew

tipafew

Location
Grand Rapids, MI
My only experience with a UMI grate was on my old SXR. I didn't have any trouble with it. A longer ride plate will help reduce porposing, but a longer plate really isn't desireable in surf where you want to keep your nose up a touch more. A shorter handle pole might help.
You also might want to look first at your prop and the gasket around the front of your pump to make sure everything is good there. A bad gasket or prop might be causing cavitation which in turn can cause porposing.
 
M

Me KawaSki

Location
Melbourne Beach Fla.
Danceswithsuperjet said:
My only experience with a UMI grate was on my old SXR. I didn't have any trouble with it. A longer ride plate will help reduce porposing, but a longer plate really isn't desireable in surf where you want to keep your nose up a touch more. A shorter handle pole might help.
You also might want to look first at your prop and the gasket around the front of your pump to make sure everything is good there. A bad gasket or prop might be causing cavitation which in turn can cause porposing.
Click to expand...
I dont hear any cavitation, the rpms dont increase without a relative increase in speed. How can I tell if my prop is bad? How can I tell if the gasket is bad? The ski takes on absolutely no water at all.
 
M

Me KawaSki

Location
Melbourne Beach Fla.
wydopen said:
i rode my 750 with no intake grate when i first got it/started riding and had no problems porposing...it must be your throttle control/weight distribution
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Throttle is usually constant. Constant spped or accelerating and it porpoises like mad. I am sure that most of it has to do with weight distribution. Take a ski that has porpoising issues to begin with, throw another 215 pounds on the back and I'm pretty sure that its gonna porpoise worse. I am pretty sure that if some 160-170 pound guy were to jump on it, the porpoising would not be nearly as bad, but that doesnt help my situation any.
 
R

restosud

practice and a long plate and hull extensions and more practice.
you could try a nozzle wedge from an sxipro.not sure if sx's had them.
 
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