09-16-2009, 11:00 AM #1
- Join Date
- May 2007
bad cavitation after intake grate replacement
My SPX used to have the best hookup or traction of any 'doo that I had owned. I made no changes to the pump area or the through-hull fitting. Now, after installing an R&D intake grate, I get bad cavitation at low speeds. Is this common? This thing used to pull hard out of the hole and now it will bounce off the rev limiter.
Maybe the thru-hull fitting wasn't that good but the OEM grate simply exposed the problem?
09-16-2009, 12:12 PM #2
What "through hull fitting" are you describing? theres your constant drain through the hull and out the back of the pump then your water inlet from the pump. Did you use a rtv or cauk to seal any of the voids and gaps. Use a 3m 5600 or so because regular rtv silicone will just blow out. I put an r&d aqua vain on my 97 xp that I sold and it didnt really help it out the hole. I didnt expect it to anyways. the purpose of an aftermarket intake grate in my book is to help it hook up better through chop and maybe through hard turns. I did not like the lean in style of that ski for turns, turned for garbage if you ask me, lean out x4s all the way!!! Though its less man handling across the chop in a strait line because of the engine being more pushed forward. That was the 97 too only with an 800 like a 96, hense a 96 is like almost 100 lbs liter. I should have looked for an xpl then instead of that ski.
09-16-2009, 04:22 PM #3
Uh, he would be talking about where the driveshaft exits the hull.
If that is sucking air it will cause cavitation.
At this point, you need to varify the clearence on the wear ring. If the SPX has a carbon seal on it you my have a weak boot or if may still have the rubber o-ring on the driveshaft which will let the collar walk forward and then the whole deal leaks both ways. You can replace that o-ring with the metal clip as the driveshafts were not any different.
I will not even touch the comment about X-4s cornering better than XPLs. To each his own.
09-16-2009, 09:22 PM #4
Bad cavitation after intake grate replacement
I will not even touch the comment about X-4s cornering better than XPLs. To each his own.[/quote]
If you read correctly " " I didnt say anything about x4s cornering better than anything or evan xpl's for that matter. I simply stated "my" prefferance of rather riding lean out, rather than lean in.
09-16-2009, 09:26 PM #5
- Join Date
- May 2007
thanks for the replies,
Well I just got an alignment tool so I intended to remove the pump and align the engine the correct way anyway. But the last time out, with the stock grate, it hooked up nicely. I did nothing between rides except change the grate and fill it with gas.
I did notice that the bars on this grate are very square for something that is supposed to see a lot of water flow.
On my next trip I will try adding pressure to the carbon ring. That has minimized the leak on another boat that I had. If that doesn't change anything then I will give it a try with no grate.
With it being late in the season I haven't seen any rough water condition with this grate. I wasn't looking for better low-speed hookup with this grate but I didn't plan to loose any either.
09-16-2009, 09:26 PM #6
Where I ride it is chopy all the time, so a top-loader to me is worth a 2 or 3 mph loss. What kind of r&d grate are you using or were using?
Last edited by Diggler; 09-16-2009 at 09:39 PM. Reason: spelling
09-17-2009, 12:56 AM #7
Like I said, to each his own. You would have liked the XPL better overall, the '97 XP was underpowered.
The grate is not causing the cavitation.
There is a point between good and bad, only the timing in relation to the installation of your grate makes it odd.
09-17-2009, 11:48 AM #8
yess yess rider preferance. I thought thats what u ment. duhh Yeah I didnt like the accelerator pump setup on it which made me realize how under powered it was. thing sucked off the line, always hit the rev limiter. the 96 xp would blow it away top and bottom. alls i had done was a bunch of crap for stability, hookup and a little speed. ss17/25 from skat trak. 88 85 r&d nozzle, top loader grate and the worx tabs, beach house sponsons, and umi steering of course. oyea when I first picked up the ski it had nothing done to other than a replaced impeller. It had a 14/19 soloas and was missing the nose boot on top of it. that thing wouldnt go over 50 and would cavitate horibly at wot, drove it home slow after that, I drove it strait to the backyard lift and pulled the pump right away and ordered a skat trak prop and everything else. what wonders the top end was like after the right prop was on it with the nose boot.
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