Is Hole Shot Cavitation Normal?

[Jdw]

hi guys I have done a lot of reading on this forum and has great information. I've searched and cant quite find the answer I'm looking for. I bought a used 2003 185 sc gtx 86 hrs on it. I have 2 older and smaller sea-doo's had no troubles so I didn't request a test drive just ran it in the guys shop(the motor runs low hr's it must work right was my thoughts). got it home took it to the lake and hit the gas and nothing but cavitation had to do some serious throttle feathering to get it out of the water. needless to say I got took. So I came here did some research and found the plastic pump problem. I have purchased a new plastic pump and ring, the old one the prop was digging into the side of it and the fils were broken on one side.(I could not find a used metal one in Canada anywhere to up grade to metal and Canadian dollar being so bad eBay was out.) That helped but still bad hole shot. I've changed bellows, carbon washer and stainless support ring still no go. The impeller looks great but you can see some wear on the surface of it almost like casting marks not sure what it is. Any ways do these larger hp machines always have cavitation off of the start. Thanks for the help.

[Jdw]

I went out and took a couple of pictures one of the Impeller and one of the ride plate seal it looks like its detaching from the plate but maybe that's normal. The impeller is so shiny because I polished it before I put it back in it was kind of rusty and rough before.

[psycho rxp]

Was it taking on water when cavitating? Check the engine mounts (broken), and carbon seal area, for a good seal. It can suck air in from the hull , if the seal is bad / leaking.

Also try a different prop (if u can) sometimes the prop splines inside the prop hub can spin.

Also how did the driveshaft splines look?

[psycho rxp]

..

[Jdw]

No it is not taking any water on to speak of there's a little in the bottom of the hull maybe a cup after about a 3hr ride. The carbon seal is new updated onewith stainless collar.
the splines in the Impeller are real good and the drive shaft splines are like new. I took it to the local dealer and had the motor aligned before I put the new carbon seal in. I don't have another prop and a new factory one is nearly $400 which is more than I want spend on a trial and error repair. I found a solas 12/20 on eBay that will cost me $360 that I may try but I don't think the impeller is my problem. but then again I don't know what my problem is. my budget is running out I really got taken on this machine. I found oil in the compressor line so I rebuilt the super charger already that cost $700. The new pump housing and parts was $450 and the carbon washer and parts was $180. So if I buy a $360 impeller I would be almost $1700 into it and may still have a cavitating pos. I'm going to run it as is until I have some more cash and maybe get the impeller this winter and see how hard it is to reseal the Ride plate to eliminate that as a possibility too.

[Kmorningstar_rxp]

What year ski? I've got an oem prop sitting here

[Jdw]

2003 185 gtx supercharged 155mm impeller i belive

[Treemn]

It could also be a pinched pump seal a very common issue. The r & d pump seal is a great addition. If you get the r d pump seal just lube the heck out when installing it

[Jdw]

If I were to silicone ther pump seal to the hull would it help to see if that's my problem. Could the uneven surface of the impeller be causing my problems it looks good to me but I have no experience to draw from.

[truck240]

Did you determine the original reason the impeller was rubbing heavily on one side of the wear ring? What do you mean by uneven wear on your impeller? Did the original owner change the impeller? If the stators (fins) inside the pump were broken I suspect a rock likely passed through it. However, your impeller doesn't looked like it has been significantly damaged. Double check to make sure that it is the correct impeller for your machine. The correct impeller is BRP Part# 267000712. The reason I suggest this is in your pic your impeller appears to have straight leading edges similar to BRP Part# 267000673 used in the 155 HP 4-tecs. The 185 HP Impeller #267000712 has much more of a radial (curved) leading edge.

2003 GTX 4-Tec SC impeller
BRP# 267000712


2003 GTX 4-Tec
BRP Part# 267000673