Squarenose cavitating really really bad

[TexasTexas95]

So, My superjet single handedly ruined my weekend. Given, it was the first time I have ever put it in water....I started her up in the water just fine and when I went to try and ride, it got zero hook up. Only enough to pull me through the water pretty dang slow. Nowhere near fast enough to get me up. From waist deep water I could push it to wide open throttle and hang on to it still. I knew it was cavitating and my weekend was over and I hung my head in shame. After work today I pulled off the ride plate and intake grate, here is what I found. The only nicks in my impeller is what you see in picture one. The gap between impeller is perfectly even and miniscule. I could maybe slide a couple sheets of paper in the gap but thats all.

The next thing I noticed is this seal and metal ring were not centered up and if I pushed on the metal ring from the side, I could move it. Is this the reason I am experiencing cavitation?

Pic from the bottom:

Pic from the back looking into the butthole of my ski:

My midshaft iooks straight and the coupler is nice and tight. When I start the ski, everything sounds normal.
Please let me know what the heck is goin on here before I lose my mind on this sucker.

 

[kraqus]

Can you move the driveshaft?
You should be able to turn it by hand and it should move almost effortlessly...


Benny

 

[chriselmore_1]

your pump seal is toast. that stock impeller looks beat up too

 

[TexasTexas95]

Ok, so while I waited for some responses, I pulled the pump apart and the "pump seal" was toast. The metal ring looked just fine, just not the rubber seal. Do yall think this was the culprit? This is exactly how it came off my ski. The drive shaft does move effortlessly once I disconnected it from the drive line. Before, it only rotated when I pulled the spark plugs and rotated it by hand, or turned the motor on. Will this impellor still work or should I save for a skat trak or something while I got it off?

 

[chriselmore_1]

that pump seal would deff make it cavitate. and a new prop would make a noticable differance

 

[TexasTexas95]

Since I pulled the drive shaft out from the midshaft, will I be able to reinstall this easily? Do I just kinda turn the whole unit till the splines line up and slide in? I dont have an impeller tool to get this stock impeller off, so I might need to leave it be for now or until I get some better funds to replace the impeller.

 

[Patrick Star]

Since I pulled the drive shaft out from the midshaft, will I be able to reinstall this easily? Do I just kinda turn the whole unit till the splines line up and slide in? I dont have an impeller tool to get this stock impeller off, so I might need to leave it be for now or until I get some better funds to replace the impeller.

Talk to jetskihaven about the shaft holder. I got that Solas tool and Yamaha shaft holder for really cheap. Besides he's right next to you in LA so you should have the part in hand in like a day or 2.

Let me know how your impeller removal goes... I have a stocker that's been on since '93 I plan on removing this summer. The only good thing about my stuck stocker is that it makes a great midshaft coupler remover.

 

[TexasTexas95]

Too bad that California is closer to me than Louisiana or I might just drive on over there and pick the part up myself. HaHa, I live at the very western tip of Texas right now, hence the "hell Paso" portion of my location. Anyway, I will see if Jetskihaven has what I am looking for. This impeller has seen better days for sure, I am just trying to weigh the pro's and con's of getting it off. I just wanna ride this dang thing already!

 

[JetManiac]

your pump seal is toast. that stock impeller looks beat up too

Right on the money. The pump seal will definately cause that kind of cavitation. The stock aluminum impellers should be illegal! Friends do not let friends run those miserable things. They cause cavitation only when used! They almost always have serious cavitation pitting on the hub and inner blade area.

If you want a low dough setup, I use reconditioned ss oem blaster impellers on sjets with good results and have cheap driveshaft tools. +tips on removal/reinstall if needed

 

[TexasTexas95]

Jetmaniac, I will hit you up when the funds come in. I have skimped on nothing during this superjet build of mine, I may as well drop a prop thats gonna have some kick to it. It just may take a couple weeks till the funds come back to me. So I guess my impeller is trash too. how sad.