impeller help

[okoutlaw83]

On my SN the impeller isn't tight on the wear ring. How do I fix this?

 

[Tyler Zane]

Can you elaborate a bit? The impeller "tightens" on the driveshaft which is pressed into the stator section (the part behind the impeller with veins) and the wear ring (or housing) is around the impeller.

 

[okoutlaw83]

There's a 1cm gap all the way around I'm confused how it even did it. I had the oem removed and a skat installed last summer. I think I'm having some blowout and it's causing cavitation

 

[okoutlaw83]

It's like the prop needs to be more towards the end of the shaft maybe?

 

[Tyler Zane]

I just talked extensively on this a few days ago. Im going to copy and past my post so be aware its not oriented towards you but its all relevant. This guy had a pump issue too.

The wear ring is the plastic or stainless steel housing around the impeller. Its like a shroud on a fan. It forces the impeller to pull and push rather than blow outwards. Per the superjet manual impeller to wear ring clearance should not exceed .02 inch or .4 mm. I figure your guessing at the gap because of the range you gave.

Now let's talk more about wear rings. If its plastic, then the wear ring is the wearable item. Some skis came with a stainless steel wear ring and in that case the impeller typically is the wearable item. It could have either because it's most likely been changed at least once.

Plastic is preferred by those that ride sandy conditions because you can change the lwear ring liner out yearly for 30 bucks. People who don't ride in sandy conditions normally prefer stainless because it last a long time. The problem with stainless is salt water can cause it to swell and sieze up the impeller.

Even if the impeller to wear ring clearance is fine, the impeller could be damaged to a point that it doesn't work effectively. It would have to be pretty messed up to do what you describing though.

You could also be sucking air from the pump cavity or bilge also.. There is a seal in front of the pump that seals against the pump shoe. If this is damaged or missing it would have a similar issue to your description. Your midshaft is to be sealed as well so the impeller can't pull air from the bilge.

 

[Tyler Zane]

Let me just set this link here for ya too.

http://www.x-h2o.com/index.php?thre...ar-rings-pump-shoe-intake-grate-parts.142220/

 

[okoutlaw83]

The ring looks perfect it's looks like the prop Is too far on the shaft. Needs to go to the back of the ski just a hair to get tight Everything looks good I'm a nob tryin to learn a little

 

[Tyler Zane]

Dont worry about being new, welcome to the X. We where all new once, there are lots of people who are willing to help and between us all there is hardly an issue not resolved.

Is the impeller tight on the driveshaft? Its left hand rotation threads. If its tight, then there isnt really any adjustment to move it forward or back and doing so doesnt change the impeller to wear ring clearance (some pumps do get adjusted like this but not this one). If the clearance isnt to spec then you must replace the worn parts.

 

[okoutlaw83]

The pump is still in the ski. How can I tell if it's tight?

 

[Tyler Zane]

Its most likely tight, i only asked because you said it looked too far forward. Anyways, you can pul the intake grate to get a hand on the impeller.

Do you have a running issue or is all of this just an observation?

 

[okoutlaw83]

Last time I took it out When I would punch the throttle it wouldn't make pressure made different sound as well. So I started looking and noticed the spacing in the clearance

 

[Magnum Mike]

if it is a huge ~ 1cm gap between the impeller and the wear ring all the way around it might be that there was a delrin insert in the wear ring pump section which has broken up and been shot out the back of the pump in little pieces.

It happened to me right before Daytona freeride this year. The engine would rev and I was able to get the ski moving slowly but there was almost no forward acceleration in the water. I was able to get back to shore under my own power but it was very clear something was wrong. Root cause was that my pump bearings sounded like baby rattler.


oops - nevermind, I read another one of your posts, sounds like you are talking 1cm gap towards the stator section not around the circumference of the impeller.

 

[westjon86]

You have to cutback your prop if you want to have it closer to the stator veins

 

[Tyler Zane]

Guys i dont thing we need to get into cut back impellers and what not just yet. This might be a completely stock SN..

The impeller blades do not have to be close to the stator section behind it but aftermarket impellers do close this gap up. Whats important and problematic is the clearance around the impeller.

The sounds could likely be shot out pump bearings. You might consider pulling your pump to go threw it. I wouldnt be surprised if a SN needed a impeller, wear ring, bearings/seals, and a pump seal.

If its not making any thrust at all and just makes a grinding noise then you may have stripped driveshaft splines. In that case you will need to replace the driveshaft and midshaft.

Whatever the cause, you need to pull the pump. If you do, look for shims and remember their placement.

 

[okoutlaw83]

Ok I'm going to go ride this evening. I'll give that ski a good look with the grate off

If I don't punch the gas or keep some weight off the back of the ski it drives well I'll be back