97 GTI cavitation

[hondoowl]

Took my 97 for a spin after I replaced the head gasket and put in new bolts. Ran great but I was in about a three acre pond at my house instead of the lake. Sucked up some moss and it logically began to cavitate. I cleaned it up, then ran great again. Took it to the lake several times and ran fine. Last weekend took it out and it started cavitating again. Could not get out of the hole or over 8-10 MPH. Got home unbuttoned the grate and got in there and found a very small amount of moss right in front of the impeller wrapped around the shaft. Removed the moss and went back to the lake a few days later. Ran better but still cavitates from start to top speed at about 30 MPH which is way south of normal. I've started tearing into it but I not having anything to compare to or experience here, looking for advice. Reading lots about wear ring, carbon ring, impeller... how do you know for sure? What are the spec's, how thick should the wear ring be? What's the gap between wear ring and impeller suppose to be?...?
Thanks in advance.
Let it rain! Without rain, we would live in a desert and there would be no place to ride!

 

[Dr Honda]

The spec on the wear ring is <0.040" gap.

If you are having bad cavitation, I would replace the carbon seal, and all of it's supporting parts. The carbon seal is not always possible to see the wear or damage.

Last thing... if you are running in moss... be VERY careful. You could be chopping it up, in the pump... and forcing it into the cooling system. I would remove the main feed hose, and look for any signs of moss. If you find it... you will need to clean the entire system.

 

[hondoowl]

Thanks, I am quickly learning these puppies are fun but hi maintenance. Just replaced starter oand voltage reg on the other one along with a couple broken exhaust manifold bolts and gasket. Had my ski boat since '89 and just did first R/R work, starter. Guess I will have to get use to this. Kids love them.

 

[hondoowl]

Ok, I have it all torn down but not having done this before I am not sure what I am looking for or at. The gap between the wear seal and the impeller is .160 so that's about 4X what Dr. Honda says. would that be enough to cause cavitation?

I also measured the internal diameter of the wear seal and its approximately 5.750 inches, I assume then if you subtract 2X .120 to the 5.75 the new diameter of a wear ring should be closer to 5.5 inches?

The seal is what looks to be some type of composite so is the wear seal and the carbon ring the same thing or what exactly is the carbon ring?

Also, behind the impeller at the back of the wear ring there is a major gap, about half an inch wide and the depth of the wear ring, is that suppose to be there or does a new wear ring have something which fills that gap.

Next question, based on what I have read, I guess I just flip the entire housing over and drive the wear ring out the front supporting it on the bolt holes / housing so pounding does not damage the front of the impeller?

Thanks in advance!

 

[Dr Honda]

The carbon ring, is the driveshaft seal. If you remove the gray, plastic cover, from behind the engine... you will see it. If your gap is 0.160... that gap is SO big... you won't build any pump pressure.

If you look in the "How To" section... you will see a post I made on how to replace the wear ring.

Here is your carbon seal....

 

[hondoowl]

Thanks, great pic's. What is the purpose of the carbon ring or "ring carbone" as its called in the parts manual? Why do you think I need to replace it to eleminate cavitation? Now i need to find an impeller tool!

 

[hondoowl]

I found the tools on the rivamotorsports site, but which one do I need (see list below) and to remove the impeller, do I turn clockwise or counterclockwise.
WR011 Tool, Removal, Solas Impeller, SD, SR Series $ 14.95

WR001 Tool, Removal, Solas Impeller, SD, all SD/SF/ST Series $ 14.95

TOOL23 Tool, Impller Removal, KAW & SD All except RXP & X-Boats $ 16.98

RWRSEASW Tool, Skat Impeller Removal, SD all models execpt 4-TEC $ 15.98

RWRSEASW23 Tool, Skat Impeller Removal, SD 4-TEC models $ 29.95

 

[Dr Honda]

Thanks, great pic's. What is the purpose of the carbon ring or "ring carbone" as its called in the parts manual? Why do you think I need to replace it to eleminate cavitation?

It's the driveshaft seal. If it's leaking... then you will suck air past it, and if air gets into the pump... you wont go anywhere.

RWRSEASW Tool, Skat Impeller Removal, SD all models execpt 4-TEC $ 15.98

Get that one. I know it will fit.

 

[hondoowl]

Thanks for the replies. I have ordered muchos parts. The only question / concern I have was a comment I read in another thread regarding the ordering affiliation between rivasmotorsports.com and the seadooforum. When I tried to order the impeller tool from the affiliated website I could not, showed not able to add to cart. When I went directly to rivasmotorsports.com, I had no problem???

 

[hondoowl]

Thanks, for impeller removal. Clockwise or counter clockwise to loosen?

 

[hondoowl]

I guess I'll just bump the starter n see which way the shaft turns and then go accordingly. Thanks.

 

[Dr Honda]

Sorry I missed this. The impeller has standard rotation threads on it. So... once you have the shaft in a vice... you turn the impeller counter clock wise.

 

[hondoowl]

Thanks, waiting on parts.

 

[hondoowl]

Got my parts, btw, Rivamotorsports, called to verify the impeller tool and recommended the WR001, which did work. That's the second time they have called in the five times I have ordered from them, the other was a question about a starter I had ordered. Total job took me about 4 hours, including a "do over" when I found the two O-rings from the bailers laying on the platform. If I did this type of work every day, would take about an hour. I highly recommend tackling this one for all the DIYers. Good sit down work. Used much of the advice I found here, the freezer worked great, plus I layed the housing in the hot Texas sun for a couple hours, probably somewhere around 130 when I put them together. Looking forward to a fun day at the lake this weekend. Thanks again!