Cavitation help

[ZXR07]

i have been reading the forum for a few years and enjoy the amount of ‘knowledge shared here. With my first post I am looking for some help. I have a 2015 AR 220 and I started experiencing cavitation last year on my boat. Last year was my fourth summer on the water with it. The problem is worse on the left side, can’t take sharp turns either side, can’t get on plane with out hitting rev limiter. I need to feather the throttles when I take off, real issue with a tube.once on plane in a straight line it isn’t too bad. Top speed with two adults and three small kids is about 36 MPH on a good day. when I pulled the boat out of the water i inspected the impellers and housings, wear rings, no obvious issues there. The intake grate looks good also. I am looking for some advice before I go to far as the boat was almost unusable by the end of last year.

thanks for any help

 

[Scottintexas]

What about the silicone on the inside of the pump area, missing or loose can cause issues,
Did you check your impeller clearance?

 

[sunbyrned]

When you say you inspected the impellers, did you disassemble them or just take a look? I had the same issue and couldn't see anything by eye, but just my disassembling and putting them back, the problem went away. I either couldn't see the debris and it fell out when removing the impeller or the impeller shaft was just not seated right somehow.

 

[BigN8]

Over the years I've seen 3 causes of severe cavitation, which is what you are experiencing. Something jamed in the impeller and wear ring. This could be small or large. Missing silicone around the intake grate and the inside of the impeller housing. Worn impellers. If you inspected 1 and 2 then it's probably worn impellers.

Another thing that could cause it that you did not mention in your initial post is the boat being over loaded. I've been out with a full boat and trying to tube and noticed cavitation but it goes away when you unload the boat.

 

[ZXR07]

I took the housing off tonight to get a better look and measure the clearance. no chips or gouges in the impeller or wear ring. I measured .004” to .01” clearance from the impeller to the wear ring.

what should I look for on silicone? Obvious missing silicone? Should I pull the intake grates and reseal?

thanks

 

[Scottintexas]

I wouldn't think your intake grate is an issue,
Here is my missing silicone thread

https://jetboaters.net/threads/cavitation-missing-sealant-in-pump-grate.884/