1990 sn 650sj ride plate/intake grate

[Jhucke]

Whatever man, I thought you actually had something constructive to say towards the post. You say my theories are conflicting but don't explain how?

I don't ride full speed because its a superjet, I like freestyle riding, jumping boat wakes (chasing them is when the porpoising is annoying), and working on tricks.

You claim rider error, but that doesn't make sense as to why I can ride a friends stock Superjet and not have the problem. Its a 2002 by the way, not an 08+ with the new hull design and pump. I can lean over my bars with my feet at the front of the tray and it will still want to do it. I can regain control by backing off throttle a bit but when trying to go flat out, after a bit it starts again.

Pump is in good shape. New pump shoe seal, clean vanes, newish 9/15 hooker. Did it with my old skat trak prop as well.

Anyhow, I still don't understand the pushback to defoam. Worst case scenario it doesn't fix it and my skis 25 lbs lighter. It will make it faster and easier to jump out of the water, not seeing the downsides here. Google superjet foam porpoising and you'll see other posts of people having a similar issue that went away after replacing foam.

"I dont go full speed often" - You dont know how to ride YOUR ski.
"Weight is not an issue" - You literally just said that reducing items encompassing the weight of the rear of the ski is not an issue.
"It's not rider error" - this is debatable.

Never pushed back against you defoaming your ski. Defoam your ski, I don't care. I said that it's not going to help your porpoising. See my avatar picture? That's me racing a 1991 superjet with heavy wet foam. Zero porpoising.

I did a quick google search and only saw you in other threads complaining about porpoising.

 

[Th3 VVay]

Google must be broken for you. Here's 3 I found in 2 min.

http://www.pwctoday.com/showthread.php?t=48736
Post 8

http://www.pwctoday.com/showthread.php?t=59367&page=4
Post 33

http://www.x-h2o.com/index.php?threads/major-porpoising-help.133027/
Post 7

You-"Please dont cut up your ski and gut the tray thinking new foam will solve it!! It would be easier to lose 25lbs off your body!"

Also you- "Never pushed back against you defoaming your ski. Defoam your ski, I don't care."

And I'm the one with conflicting statements?

P.S. Sorry OP for hijacking your thread. I'll let you know if de-foaming fixes my issue.

 

[Jhucke]

Google must be broken for you. Here's 3 I found in 2 min.

http://www.pwctoday.com/showthread.php?t=48736
Post 8

http://www.pwctoday.com/showthread.php?t=59367&page=4
Post 33

http://www.x-h2o.com/index.php?threads/major-porpoising-help.133027/
Post 7

You-"Please dont cut up your ski and gut the tray thinking new foam will solve it!! It would be easier to lose 25lbs off your body!"

Also you- "Never pushed back against you defoaming your ski. Defoam your ski, I don't care."

And I'm the one with conflicting statements?

P.S. Sorry OP for hijacking your thread. I'll let you know if de-foaming fixes my issue.

You-"Please dont cut up your ski and gut the tray thinking new foam will solve it!! It would be easier to lose 25lbs off your body!"

Nice try but I didn't say this.^^^

Skimmed those threads quick and it looks 70% of the posts say noob rider error, 29.5% say to change equipment. Sorry you're upset about my comments. Good luck, superjets are fun at high speed, but you need to know how to ride them.

 

[Ryan Stewart]

Did you ever fix your porposing on your SJ? Ive got an old one with a new 701 engine, skat impeller, and i doubt its water logged because i just foamed it. But who knows....maybe ive got a leak in my new footholds . Im about to buy a jet dynamics extended concave . Seems like the biggest plate i can find. I weigh 210 and really know my ski. My kawasaki doesnt porp at all. Ive spent weeks making sure it wasnt positioning or rider error. Flat water i basically hop like crazy

 

[mikidymac]

I have a 1991 with a 701 swap but basically stock with an old scoop grate and the short Jet Dynamics ride plate. 199 lbs and 6'3" tall with no noticeable porposing.

 

[Ryan Stewart]

So if i did waterlog the rear of my jetski,whats the best courseof action to replace the foam. Where do i make my cuts. Or am i just cutting out the tray, sides, footholds, sidewalls all in one cut and just put it bCk together in one piece after gutting the wet foam. Sealing it then making holes and filling it with foam.

 

[mikidymac]

Do not cut out all of the tray as it will be a nightmare to rebuild. You can see my build thread of what not to do. You only want to cut the sides and bottom out enough to get access to the inside of the tray but leave plenty of room to lay new glass to put the old pieces back in.
Project Boat Anchor

 

[Quinc]

Your tray is probably fine if you just did it. You need to ride more. I cut 3" off the back of my 1990 SJ and then cut my stock ride plate even shorter and have no problem with porpoising. You need to get your weight further forward. If you stand with your toes touching the front of the tray does it purpose as bad?

 

[Jhucke]

Your tray is probably fine if you just did it. You need to ride more. I cut 3" off the back of my 1990 SJ and then cut my stock ride plate even shorter and have no problem with porpoising. You need to get your weight further forward. If you stand with your toes touching the front of the tray does it purpose as bad?

Plus one. When cruising, people think you need to be in this super aggressive alternating feet, elbows up riding stance. In reality, if the water isn't.. waves.. you can literally stand straight legged in the front of the tray and just drive around with no proposing at all. The previous guy who made this thread fixed his issues by riding more, guaranteed.