Cavitation?

[Bdt1967]

Saturday we were driving across the lake had been cruising for around 5 min at around 5k-5.5k RPM enjoying the scenery when all of the sudden the starboard engine quickly jumped in rpm and stopped pushing. I killed both engines, inspected the engine seemed good externally, so I fired it back up, throttled it up in forward it almost instantly jumped to 7k a had very little to no jet. I put it in reverse and tried this time it ran up in rpm but not instantly up to 7k like before. I put it back in forward and it took off just like normal, no problem at all. The next day we burned an entire tank of fuel without any issues. Could I have sucked something into the intake? I noticed a lot of sea grass floating in the lake this weekend, I am guessing thats what it was, my only problem with that theory is, I would have thought that 5000 rpm would have been enough to chop any of that stuff up.

 

[Elite6]

Weeds have a tendency to wrap themselves around things causing turbulence for the water stream and therefore I imagine thrust issues. Those weeds would never make it to the blenders.:reddevil:

 

[Wezz]

The weeds get caught in the intake grate and restrict water flow, that meens no thrust, sometimes if you shut the motor off they will drop off and you good to go but there are times you may need to go for a swim and pull them off by hand.:ack:

 

[97gsxRIDER]

make sure the ski is turned off

 

[HodgesZ28]

I dont have an issue with cavitation when WOT or just cruisin at like 30mph and up "when I am on my plane" but when i go from a stopped position it cavitates till I get on my plane. The port side breaks loose so then I have to push the starboard engine full board to compensate for it. I also have this problem after I do a 360 and I go to pull out of it, it just cavitates and I have to do the same thing with the starboard engine......what would cause this? Is this normal? I don't have any weeds or anything in the grates or the impeller.

My dads friend who has the exact same boat as I do said there is something in the boat that keeps it from cavitating like a tube or something? And he said his got clogged with sand from being in the bay.....mine has been in freshwater so I know thats not the issue. Also the two little holes that spit out a stream of water "like a pee hole" in the back of the boat, the one was fixed by a shop but they used silicone to hold it in place and instead of a steady long stream, I have a tiny little dribble coming out of the whole......could that be the problem? Any input would be great as I am still a noob with this boat.

 

[yelah]

i think im having the same problem......

 

[HodgesZ28]

i think im having the same problem......

Maybe somebody will chiggiddy chime in and give us their .02

 

[yelah]

well, i did a little digging and found that a few people have had the same issues with the same boat as us. Conclusion: carbon ring leaking air into the jet pump. try taking your pto cover off so you can access your carbon ring easly. squirt a little oil on the sealing side to the pump (or just oil the whole thing real good), then as soon as your done doing that do a whole shot from a stop to WOT. See if it improves your cavitation problem. It worked on mine today. im going to replace the carbon ring on mine ASAP. hope this helps.

 

[SteelPimpin]

High Rev with no go

I learned the hard way with a friends recent purchase this is most likely caused by your wear rings being damaged. This is the rubbery liner around the impeller. We took the pumps off and took them to SeaDoo local and had this replaced. Helped on one side still trouble with other side. Was told yesterday these are now being made from stainless steel which is good and bad. The good= they last longer. The bad= If you pick up a stick or rock it will damage the impeller instead of this wear ring. I think when I replace mine I will go with the SS.

 

[HodgesZ28]

Whats the price on something like that? And how hard is it to pull a pump out to see if the wear rings are bad?

 

[SteelPimpin]

On a 1996 Speedster it was very easy. Four nuts and the linkage for the F and R and steering. Takes about 20 min. The only hard part was getting the spline to lineup on the reassemble. Not too bad.

SeaDoo charged about 300 not sure exactly I did not pay for it. It would require a few special tools to do yourself. Took them about 4 hours.