Cavitation after new wear ring. Pics

[joaquin12345]

So I have a 2002 Seadoo GTX 4tec limited. Has the 1496cc engine. Not supercharged. I bought it last year and at the time was told it had a bad fuel pump and mechanic quoted this person $1000. Anyways took it home took out 1 year old gas put new gas new plugs and it fired right up no problems at all on water hose. Took it to the lake and from standstill to wot it would slowly take off rpm's at max of 7k. Anyways if I didnt go wot i could get it up to speed. Well was end of summer so i just winterized and stored. This week I took out the pump and of course the wear wing was pretty tore up kinda seemed like the impellar had chewed it up. Anyways took everything out had no issues. Splines on shaft looked great no problems. Installed new wear ring, purchased from sbt, the white kind. After installing did notice that the impellar spun but was tighter then before. Had to give it a budge with wrench, not hard just wouldnt freely spin by hand like before, but there was about 1/8 gap with old chewed up impellar. Put everything back together and took it out all day today.

After taking it out, instantly noticed it felt alot better however I still have cavitation. I played around with it and this is with myself 175lbs and gf 130lbs on the back with me. When I got from still to wot it instantly revs up to 7k rpms and takes off like if I was spinning out. So what I had to do was from stand still i would go about 3/4 throttle where I would rev up to 6k rpms until i hit about 25mph, which i would reach just fine, just no throwing me back and definately wouldnt be able to pull up a wakeboard, then I could go wot and notice the power. While i would be driving as long as I was going 25mph or faster I could let go of throttle then wot and it would go, pretty impressive actually but under 25 and doing that it would just rev up.

Im assuming that the fuel pump is fine as it ran all day, never hesitated. At idle im doing about 1500-1700rpms. My fastests speed was 52mph, which i felt should be faster but never had a 4tec monster. As they are huge compared to x4 hulls. My clearance on the new wear ring is where its suppose to be at, prob less then dime thickness. Im just stumped on why it is that i still cant go wot off the start. I attached pics and I assume everything is where its suppose to be at impellar at right area as driveshaft was snug when put on. Anyways im stumped and would appreciate some help. By the way was lucky I didnt sink it as I forgot to attach the two hoses that run into the pump from the inside. Had already drove around about an hour then parked took off seat and noticed it pouring in had about an inch but I guess bellows kept water out.

Anyways what do yall think could be my prob, what speeds are yall getting on these 4tec seadoos??

 

[devonte007]

Sounds like you still have some pretty bad cavitation. Your old wear ring was definitely shot. You stated that your new wear ring came from SBT, do you know if you got a Seadoo OEM wear ring or an aftermarket? Some people have described problems with aftermarket wear rings not working well with loose fit. If you did not get an OEM ring, then you may want to make sure it fits into the pump well, nice tight fit and not loose. Also take a close look at the pump itself, sometimes these older plastic pumps can get warped over time. If they are not perfectly round then the impeller and wear ring will never seat right and you will always have cavitation.

If that all checks out then the next thing to check would be your carbon ring seal. The drive shaft seals wear out over time and are a maintenance item. Considering this ski is 10 yrs old, it is conceivable that you need to replace the carbon seal and rubber boot. For the most part the carbon ring does not really wear out, but the rubber accordion boot just looses flexibility over time and it can cause an air leak and cavitation. I have heard you can test the seal by putting a couple zip ties on the boot to force more pressure on the stainless steel ring, and even glob some heavy grease on the seal. It will temporarily seal any air leak at the carbon ring and should temporarily fix the cavitation. Do some searches for the 'drive shaft seal' 'carbon ring' and you'll find a lot of info and techniques to diagnose this.

Hope this helps, good luck!

 

[red2blue]

Heh..."less than a dime"? Better be a lot less than a dime...like I dunno.....mine reads something like .004-.006 of an inch.

Idealy...oem spec was somewhere around .025-.016...or thereabouts.

You thinkin about replacing that prop?...or having it refurbished?

 

[joaquin12345]

Do you guys glue the new ring to the housing. I saw on the micro fische page something about adding locktite to the impellar.

red2blue, the gap is less then a dime. probably about 2-3 paper thickness. Is there anyway to tell if the impellar is bent by just looking at it. what exactly would I be looking at. Also I would think I would have some type of vibration while on the go whick I dont. Also I was wondering if anyone knows if the same pump from a 2003 Seadoo Gtx SC matches the 2002 GTX Limited non supercharged. Its same engine, same body minus the sc. If so I have the other ski that is wrecked. I work next few days if not I would just pull it out and check but over the next couple of days if someone already knows that answer it would be great.

 

[Wenier]

If its the original prop id replace it with a solas one or similar. I recently did the wear ring and still had some cavitation with the standard prop then I switched out the prop for a solas concord sr-cd thing for the 155hp 4-tec and it is an amazing difference, just hooks up and goes.

 

[red2blue]

Pull the pump...gonna need a prop removal tool (get the long one) a 12mm allen socket...get that prop outa there and set it on a bench. Now take a rule...preferable a metric but any will do. Check the blade heights against each other...leading as well as trailing edges. You can have these things off 4-5mm from one another with no real difference in feel...but man will it make a diffeence in performance. If someone has "straightened things out"....how much clearance you have between the prop and wear ring is also crutial. Use a good set of spark plug feeler gauges. Some older rings used a set screw..most are just friction fit. Put the pump it the freezer for an hr or so...the ring will fall out...reverse procedure when reinstalling. Dunno bout your other pump. pull it and take a look side be each. No?

 

[devonte007]

The wear ring is not glued to the impeller housing, just a tight friction fit which is why some aftermarket rings are a problem; they do not fit tight enough.

Loctite 518 or similar (anaerobic gasket maker) is used to seal the machined mating surface between the impeller housing and the venturi. Just clean the old stuff off with a soft wire brush, and apply a little bit all around the housing. Then mate the two items and screw them in. The screws that hold on the venturi and pump are secured with blue loctite so they don't back out. There should be no loctite on the impeller itself, in fact the manual states to use anti-sieze lubricant on the impeller shaft not loctite.

If you are new to working on the pumps it would probably be a good idea to download the manual and read it in detail before you start working. You can download the manuals from this site, just click the 'manuals' link at the top of the page.

Not sure about your other question about swapping pumps from the 2003 Seadoo Gtx SC and the 2002 GTX. I do know that the pumps are a bit different and larger for the ski's with supercharged engines vs. N/A models.

 

[Michael211_2000]

That impeller looks pretty beat up, too. New wear ring + new Solas impeller would definitely improve performance.

- Michael