Thread: Cavitation issue: worried
08-29-2005, 09:23 AM #1
Cavitation issue: worried
Guys: I need a little help. My ski has developed a new problem. Lately, the holeshot has been great most of the time, but has been spinning on occasion. Well, each day, it seems the occasional spin is becoming more and more frequent. One minute the holeshot is fine, and the next minute it's horrible! RPM's are still 8000-8050 on top end though. New clutch 20 hrs old. There is absolutely nothing in the grate/pump. I also run a ss wear ring. Prop is fine. The green impellor cover (?) is in place and tight.
It happens in deep and shallow water alike. It is soooo bad that I have to feather the throttle to get moving!!!! Still running 76-77! The pump sounds like its shuddering violently when cavitating. Any thoughts? I do not have the double-bearing or the 5 mm mod. Could this be the source?
08-29-2005, 09:35 AM #2
I have heard of the rubber seal between the pump and hull not making good contact. Either by getting bumped out of position during installation of the pump, or by not having a clean surface to mate to. Just a thought.
08-29-2005, 09:35 AM #3
if you have burn marks on your wear ring i would have to say you need a pump mod done and possibly a new impeller maybe a wear ring, my impeller looked just fine and teh clearances looked ok too but they werent, it seems that the impeller wears more than the ring, you are having the same exact problem i am having, and it is a shaft deflection problem, personally i would start with the ppg mod, jerry did that one and his ss wear ring looked like it hadnt been touched,
08-29-2005, 09:44 AM #4
Your right SD02. I took for granted that the wear ring and impeller had been checked for scoring, that should be done first , my bad.
Being the tight- wad that I am, I look for the cheap easy fixes first
08-29-2005, 09:59 AM #5
Seadoo02xp - I have a little scarring on the wear ring, but like you, might be missing some damage. Did you do the PPG mod? Why is it so intermittent though? Do I need to replace both prop and ring as well?
Medic - I agree w/ you. I'm always looking for the easy fix. I guess it's denial.
08-29-2005, 10:50 AM #6
what if you are getting this same problem on an 800 built that has a Skat trak Pump Wear ring and prop both look good!
08-29-2005, 10:58 AM #7
i wouldnt just go replacing parts, it can be intermitttent just like mine was due to heat fade, after i sit for a long time with the engine off then immediately start it and nail teh gas it wont spin out because the engine is so heat soaked that it doesnt have the regular power output as when it is at operating temp, this could be a possibility as to why it is intermittent, i would advise you ship your pump to ppg, and whatever needs to be replaced they will let you knwo and take care of itm usually around a week turnaround depending if you wanna pay for overnight shipping, buuuut, it could also be something as simple as a seal, dont rule out teh little things either, i was just describiong a scenario that i have had that exactly matches yours, regardless of what kind of setuo you are running i think the pump mod is a good idea, right after the charger clutch the pump is the second weak link in these boats
08-29-2005, 11:36 AM #8
Appreciate the info. I really am not sure about the soak, but the pump is obviously the cause. Tonight I will be pulling the pump and checking seals and then depending on what I find might send the whole thing to Glen @ PPG. Thanks.
08-29-2005, 03:52 PM #9
I had the same problem. Mine was the rubber seal in front of the wear ring. It was smashed in a corner where I put it back together. Replaced the seal and good to go.
08-29-2005, 05:32 PM #10
I had a bad cavitation problem too. It ended up being the carbon seal around the drive shaft was worn enough to suck air from out of the hull causing it to cavitate. How many hours on your doo? It started leaking shortly after this . Now with new seal no more cavitation.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By Straightchillin in forum Polaris Open DiscussionReplies: 4Last Post: 07-09-2008, 10:27 AM
By Hockey369 in forum Yamaha Old School SkisReplies: 12Last Post: 06-25-2008, 09:36 PM
By ba6636 in forum 4-Tec PerformanceReplies: 8Last Post: 06-20-2008, 06:40 PM
By r4ma1r in forum 2-Stroke PerformanceReplies: 5Last Post: 05-28-2008, 06:29 PM
By BrandonB in forum Kawasaki Open DiscussionReplies: 9Last Post: 06-09-2007, 05:37 PM