FX-1 Major porpoising......help

[UneducatedFX1]

Hey People I Need Some Help With Porpoising ASAP, There Are Some Washers At The Back Of The Ride Plate Between It And The Hull (I Have No Idea What For) And The Ride Plate Is Extended And It Still Porpoises, HELP Anyone.

 

[JT_Freeride]

What kind of ski? What is your weight and height?

 

[balsam lake glass cutter]

time in the tray

 

[JT_Freeride]

time in the tray

Agreed my friend just picked up a SN and he Porpoises constantly and all he did was blame the ski. So I hopped on it and not once did it porpoise. It's all about how you ride. Like said above you need to practice.

 

[UneducatedFX1]

What kind of ski? What is your weight and height?

Its A Yamaha FX1, Im About 5'10 and I Weigh About 8-9 Stones (120 Poundsish)

 

[UneducatedFX1]

Agreed my friend just picked up a SN and he Porpoises constantly and all he did was blame the ski. So I hopped on it and not once did it porpoise. It's all about how you ride. Like said above you need to practice.

See I Have No Doubts You Being Wrong But I Have A Mate Whos Ride Superjet And His Weight and height Are practically the same as mine and he had ago on my FX1 and it still porpoised

 

[Vumad]

The washers are to angle the ride plate down, which drives the nose into the water deeper, which can improve traction when riding aggressively.

There are lots of things that cause porpoising. The angle of the ride place can drive the nose down causing it to bounce. Your weight too far back can make the nose too light. Whatever model ski you're riding may just do that. Almost every ski can do that in the right conditions. It's really had to answer your question since you provided almost no information.

What model and year ski do you have?
What modifications do you have to the hull?
Do you have sponsons?
What modifications do you have to the power?
How long is the pole?
What is your height and weight?
Have you changed anything in the ski that moves the weight of the parts to different places?
What are the odds your foam is severely waterlogged?
What are the conditions when this happens? (Speed, chop, amount of fuel in the tank, etc?)

Imagine you have a child and you bought that child a car. That child comes to you and says, "Dad, the car drives funny. I need you to fix it." Hands you the keys and walks away. You'd just be standing there scratching your head thinking, "Where do I start?" That's kind of what you just did to us, except, you didn't even tell us what kind of car it is.

 

[Vumad]

See I Have No Doubts You Being Wrong But I Have A Mate Whos Ride Superjet And His Weight and height Are practically the same as mine and he had ago on my FX1 and it still porpoised

Maybe he doesn't know how to ride a FX1 either?

I've never ridden a FX1 before, so I can't advise you how to correct that issue.

A simple place to start is to remove those washers and see if it helps. It could be preloading the nose into a jump.

 

[lazyt747]

Is the back end sinking when you ride? Does the ski seem much heavier than usual?

 

[UneducatedFX1]

The Foam In The Tray is definitely not waterlogged (as i'm pretty sure theres no foam in there, as it sits low in the arse end but is very light and has had the footholds done by a previous owner) It's An FX1, Im 5,10 and weigh 8-9stones (120 Pounds), Theres No engine mods or hull mods (besides foot holds which i'm pretty sure has nothing to do with it) my friend could be riding it wrong but his stock sj doesn't bounce as much as my FX1, the ski is used for freestyle so that may explain the washers (if i took them out would it really stop porpoising), its a stock FX1 pole, and it porpoises on glass water( When i'm the only one on the lake so its super flat), i stand in the surf/racing stance (left foot top of the tray, right foot in the back right foot hold, bit weird i know), Does That Help ?

 

[lazyt747]

Wait, the back isn't foamed?

 

[UneducatedFX1]

Wait, the back isn't foamed?

I Dont Think So Im pretty sure its been replaced with a lighter material

 

[Mdavies_02]

I Dont Think So Im pretty sure its been replaced with a lighter material

You contradict yourself slightly. Post #10. "It sits low in the arse but is very light".

No foam and sealed provides the maximum boyency with the major risk of sinking if there is any chance for water to get in.
FOam provides boyency at the costs of weight and risk of getting wet foam.

If it was light, it would require less displacement and sit well above the waterline.

Although you may think the ski is light (Compared to a 350lb SJ) It may in fact still be waterlogged to hell. If the footholds were not installed perfectly, or if your hull has any cracks whatsoever (most do) then water will gradually fill up the rear of the hull. Most solve this problem with drain plugs.

Having a SJ rider try out your FX-1 doesn't clarify things must either, because they are vastly different hulls.

Next time your at the lake, take a picture of the ski from all four sides well it floats and post them up. Along with all the information Vumad asked for

 

[Quinc]

Stand as far forward as you can in the tray and see if it helps. However, reading is not going to help, you need to keep riding and eventually it will click. What also might help is if you make another video and post it. =P

 

[UneducatedFX1]

You contradict yourself slightly. Post #10. "It sits low in the arse but is very light".

No foam and sealed provides the maximum boyency with the major risk of sinking if there is any chance for water to get in.
FOam provides boyency at the costs of weight and risk of getting wet foam.

If it was light, it would require less displacement and sit well above the waterline.

Although you may think the ski is light (Compared to a 350lb SJ) It may in fact still be waterlogged to hell. If the footholds were not installed perfectly, or if your hull has any cracks whatsoever (most do) then water will gradually fill up the rear of the hull. Most solve this problem with drain plugs.

Having a SJ rider try out your FX-1 doesn't clarify things must either, because they are vastly different hulls.

Next time your at the lake, take a picture of the ski from all four sides well it floats and post them up. Along with all the information Vumad asked for

When you stand on it with your feet in the foot holds it sit lows in the back of the ski (sorry should of specified more) and just seems to be very light in the back of the ski, compared to my 550sx (yet there sort of similar, tray width wise)

 

[DangerBoy]

leave the washers, your stance is fine,you just need to weight the nose .try bending you knees and leaning forward, FX-1s like you to ride with your shoulders over the bars elbows out. you cant stand straight or lean back while riding them
Db

 

[UneducatedFX1]

Stand as far forward as you can in the tray and see if it helps. However, reading is not going to help, you need to keep riding and eventually it will click. What also might help is if you make another video and post it. =P

I'll have another video up soon

 

[UneducatedFX1]

leave the washers, your stance is fine,you just need to weight the nose .try bending you knees and leaning forward, FX-1s like you to ride with your shoulders over the bars elbows out. you cant stand straight or lean back while riding them
Db

Thank You So Much This Is The Answer I Was Looking For Thank You

 

[lazyt747]

I was going to say waterlogged as well, if like to see a picture of it in the water though to see its floating stance.

 

[djraider700]

Do you have an intake grate too? Some aggressive grates will pull the ski down in the rear and, coupled with an extended or shimmed ride plate, will act against the ski trying to plant the nose. I had this issue back when I had a kawi 750. Had the ride plate shimmed and you could stand on the nose of the ski and it still hopped up and down. Swapped out the washers, installed a stock grate and it was smooth as butter from then on. Hope this helps. Good luck!