Super Jet cavitation in surf question

[IWannaYama]

So Im pretty frustrated with the cavitation issue I get when I ride in choppy waters both feet back in holds.. I dont think its normal because other superjets I rode dont have the issue nearly as bad, (although one of them had a mag pump). Im wondering if its just the nature of a stock superjet. I do have a riva grate, -4" pole, stock ride plate, 0 bars.. Wondering if its because im 6'1 200 lbs and I have to much weight on the back allowing air to get in pump?? If i ride surf stance its much better but Id like to know whats going on. Would sponsons help? Maybe a worx 201? Its a 03 RN. THanks

 

[deftons56]

What prop do you have?

 

[kevbo]

Old impellers with stock grates dont do much in white water. At minimum you need a good grate and a pitched down Concord or Skat 12/17. A hooker 9-15 is even better in white water.

 

[IWannaYama]

pretty sure it has a solas concorde 13/17. It does have a riva grate

 

[wydopen]

you answered your own question in the first post...

step out of the footholds..

could also have something to do with throttle control if your setup is normal otherwise..

 

[waterfreak]

check your mid shaft housing! If the rubber is separated from the aluminum, then it will suck air from your engine compartment under load

 

[IWannaYama]

you answered your own question in the first post...

step out of the footholds..

could also have something to do with throttle control if your setup is normal otherwise..

I just prefer both feet back when I'm going to do a nose stab or anything..
Maybe it's time for a front foot hold and surf stance practice

 

[IWannaYama]

check your mid shaft housing! If the rubber is separated from the aluminum, then it will suck air from your engine compartment under load

How do i do this? Remove the coupler cover?
So it's not my impeller?

 

[JamesG]

skat grate plus lower pitched impeller minimizes cavitation. try brapping or holding steady throttle. find out where its happening to diagnose it. I agree with wydopen on this one.

 

[djraider700]

Definitely getting air in somewhere. Check the pump seal and, as others have mentioned, the midshaft. If not those, check the impeller and possibly the pump stator for any damage. I ride a stock intake grate in the surf and have no cavitation issues.

 

[Vumad]

Definitely getting air in somewhere. Check the pump seal and, as others have mentioned, the midshaft. If not those, check the impeller and possibly the pump stator for any damage. I ride a stock intake grate in the surf and have no cavitation issues.

If it happens on every SJ he rides, there are only a few possibilities...

Everyone he knows has a stock SJ or the same minimal upgrades.
Everyone he knows is a bad mechanic.
It's his riding style.

 

[BruceSki]

Loose nut behind the bars.

 

[sethrrogers]

Install a front foothold or a strap. Learn to ride surf stance a little more and switch back to the rear holds before the face of te wave if that is what you prefer. I also have an 03 with stock pump, worx and 13/17.. I don't notice a problem at all using this technique. Besides.. You'll honestly enjoy riding surf stance much better as the extra weight up from will help keep the nose down enabling you to cut across the surf much better. I know it's only my opinion but hopefully it helps. I even ride surf stance at the lake 90% of the time now as well...then again I don't own a freak with a liter 2 stroke pulling FW aerials so it works.. Good luck man. You still need to come up to NC or SC and ride w chase and I.

 

[Vumad]

Check out the Tom21 front toe hold. Price is reasonable, quality part, holds the extinguisher. Can switch to a lowered hood and stay legal.

 

[KTM434]

If you're riding your SJ in the surf and it hooks up well when you ride surf stance but cavities when you're stuck in the footholds then your SJ is setup perfectly and it's trying to teach you how to ride in the surf. Don't change the ski

 

[djraider700]

If it happens on every SJ he rides, there are only a few possibilities...

Everyone he knows has a stock SJ or the same minimal upgrades.
Everyone he knows is a bad mechanic.
It's his riding style.

Didn't realize it was happening on every SJ he rides. Gotta be riding style then I'd assume.

OP, are you porpoising while riding in the footholds? If the front end is bouncing up and down while you ride, it could cause the pump to unhook.

 

[IWannaYama]

Didn't realize it was happening on every SJ he rides. Gotta be riding style then I'd assume.

OP, are you porpoising while riding in the footholds? If the front end is bouncing up and down while you ride, it could cause the pump to unhook.

No I said It didnt happen on the other ones I ride. It doesnt bounce up and down it just sucks air i think and i lose momentum and engine revs up. Super frustrating when I miss out on waves because of this..