Need help with cavitation on Yamaha VX Cruiser

[Jameson Clark]

Since getting my 212x this spring, I have realized how much knowledge there is on these forums, so instead of trying to join a jetski site, I figured I would reach out to y'all that I've gotten to know instead.

I have a 2007 Yamaha VX Cruiser that me and my brother and sister inherited when my father passed away in 2014. All three of us also have boats so the ski only gets used a few times a year when we all get together on the lake for the weekend. Otherwise, it just sits around.

Anyway, recently when we've taken it out, it still runs great and purrs like a kitten but it has lost all its power out of the hole. Still runs about the same top speed (46-52 depending on rider and water) but it just shoots straight to the rev limiter coming out of the hole until it starts building some speed. So, I have learned enough this year about my boat to know this is cavitation, but I have no clue what to look for as the cause. Can anyone point me in the right direction to start figuring it out?? Thanks for any help!

 

[itsdgm]

Check the pump and pump shaft for any debris (even a piece of fishing line can cause cavitation). Also check the impeller for damage. Finally, look to see if there’s any sealant missing in the intake or pump area.

 

[Cobra Jet Steering LLC]

As previously stated there is probably something sucked up in the pump it only takes a small amount of plastic or a fishing line to cause serious loss of hole shot, look in the pump but often it is between the impeller blades and not easy to see .

 

[boudin]

If there are no obvious debris, pull the pump and check wear ring clearance, and the condition of the impeller. Post pics here.

You can also try pulling and then sealing the pump shoe.

-Greg

 

[Jameson Clark]

I will try to get some pics taken tomorrow morning before Florence gets here. Thanks for the help guys!

 

[Seadeals]

They pretty much covered it. If you ever decide to sell it, let me know. We are close and I eventually want a ski that matches my 2006 SX210 engines. I like the idea of running a fleet with the same engines. I got a small impeller ding on the leading edge that caused cavitation. It was small enough I was able to dress it out and restore performance. Hopefully Florence will “peter out” but who knows.

 

[Jameson Clark]

I was able to get a picture of the impeller from the rear of the ski. Nothing really obvious caught in there anywhere. Couldn't get a picture from the bottom, but I'll pull the grate and get a picture from there this weekend. There are some dings on the impeller, just don't know if it is enough to cause this much cavitation.

 

[Cobra Jet Steering LLC]

Like I said it is probably in between the blades and you can't see it looking in the pump, you may need to pull the pump to see what is in it.
Your leading edges look dinged up . In comparison I have over 600 hours on my impellers and way less dings on the edges so you may be backing off the trailer or beach or something similar like hitting reverse when cruising into shallow water kicking up rocks shells etc into the pump. Just possibilities.

 

[Jameson Clark]

Like I said it is probably in between the blades and you can't see it looking in the pump, you may need to pull the pump to see what is in it.
Your leading edges look dinged up . In comparison I have over 600 hours on my impellers and way less dings on the edges so you may be backing off the trailer or beach or something similar like hitting reverse when cruising into shallow water kicking up rocks shells etc into the pump. Just possibilities.

There is absolutely no telling! This was a rental ski my Dad bought for his house boat quite a few years ago. When he passed away, we got it for the grandkids of the family (me and my siblings kids) and it gets ridden by them when we go out and others with little jet ski knowledge about beaching and such.

How big of a job is it to pull the pump on these?

 

[Cobra Jet Steering LLC]

It isn't all that difficult to pull the pump as long as it isn't stuck .I have a special slide hammer I made just for getting the pump out when it is stuck. if there is something large in the impeller you would not be able to get it to go very fast so what ever it is either damage to the impeller or some fishing line , small piece of wood or some other item lodged between the impeller blades usually you have a better shot of seeing it from under the ski looking up in the intake grate.

 

[Jameson Clark]

It still runs 45-50ish, just takes forever coming out of the hole.

 

[Cobra Jet Steering LLC]

Sometimes if you just pull the intake grate you can see up in between the impeller blades from under the ski. I believe it will be some small object or piece of plastic I can't begin to remember all the things I have had lodged in my jet pumps from plastic shopping bags to toys and once a flattened beer can , once I even got hung up on a cast net someone threw from a bridge and just left it in the water when it became entangled under the Tierra Verde bridge.

 

[Jameson Clark]

Little update, my brother has the ski with him for now and the cavitation has gotten a good bit worse. He decided to pull the pump today and this is what he sees... I am still new to jet drives myself so any help is appreciated.

 

[Scottintexas]

it's hard to diagnose performance issues, my impellers were 10x worse than yours and I didn't have any real issues, others get one small ding and it causes problems,

I would say the gap looks a little big on the outer edges but you would have to measure that with feeler gauge to confirm what is normally acceptable,

a new impeller is only $150. and easy(normally) change out (you could even take it to a pwc shop to break the old one off),

he needs to pull the impeller/shaft out of the housing to get a better view of everything,





.

 

[Cobra Jet Steering LLC]

The impeller doesn't look all that good and the distance from the edge to the liner looks considerable but I have seen worse so not conclusive from the pictures although suspect. How are the bearings in the pump turn easy and smooth.

 

[Scottintexas]

I'm confused,
where is either the bearing cone assy or the impeller shaft?

did he remove the shaft from the impeller still in the housing?

 

[Jameson Clark]

Y'all excuse me on not having the best info. I am on the phone with my brother and I haven't been in one of these personally yet either. I'll keep flowing the pictures to y'all as I get them. He checked clearance between the impeller and housing. 1.13mm between the edge of the blade and the housing.

He had already taken the cone off for those pictures, shaft is still in the ski. Bearings turn smooth even with the water intrusion it seems to have had.

 

[Scottintexas]

according to Boudin's post #4 above the clearance should only be .35-.45 mm

with a .6 clearance limit,




.

 

[Jameson Clark]

So at this point, do I just buy a new impeller or is a housing needed as well?

 

[Jameson Clark]

@Cobra Jet Steering LLC any thoughts?