Yamaha Jet pump all-stainless wear ring assembly

[PSG-1]

For those of you who are running yamaha PWC jet pumps in your boats, this may interest you.

If you've dealt with the problem of corrosion causing the stainless liner to swell, this is the answer to the problem:




Now, before you say that's a lot of money....check out the OEM price (part #10), for the inferior aluminum model with a thin stainless liner, which is just going to do the same thing again......



My wear ring has a high spot, and the impeller is clanging and banging like crazy. So, I ordered an all stainless one. It arrived today.




You can clearly see this is a one-piece design. No pressed-in liner, it's solid stainless.




Now I'm just waiting on my new impeller from Impros, then I can take the pump apart and replace the impeller and wear ring, and get going again.

Here's a link to the site I ordered the stainless wear ring from:
https://www.atlanticjetsport.com/index.php?l=product_detail&p=1711

 

[Bookerf]

Nice, post a pic of the impeller when it arrives.

 

[amk]

Nice I was considering the same let us know if you get any improvments

 

[PSG-1]

Got my impeller from Impros today.



Solas Concord YD-CD 14/20, re-pitched to 14/21.



Just to show how short the driveshaft really is in my boat. Also notice the wrench flats milled into the shaft. This is necessary for impeller and driveshaft coupler removal.



Old impeller and wear ring, Solas YD-CD 13/19. Compared to the new impeller and wear ring, this one has a lot of clearance. Probably losing about 2-3 MPH because of it



This one shows the high spot caused by crevice corrosion between the thin stainless liner and the cast aluminum body of the wear ring.

 

[PSG-1]

This thread is posted under "outboard jets", when it should be under "inboard jets" .....as this part is for PWC jet units.

 

[okavango]

Hi PSG
Have you run the new wear ring and impeller yet, any noticeable improvement?

 

[PSG-1]

I have not been on the water with the jet boat since installing the new wear ring and impeller. But I plan to test it out soon, and see how it does.

 

[okavango]

I have not been on the water with the jet boat since installing the new wear ring and impeller. But I plan to test it out soon, and see how it does.

I notice you have the Wet Wolf Adjust-A-Thrust cone in your pump, please refresh your thoughts and opinion on this product.

 

[PSG-1]

The AAT cone does seem to make a difference in hole shot, and on top end. It uses a spring-loaded shuttlecock that moves back and forth, dependent on water flow through the pump. At low flows, the shuttlecock is retracted, allowing full water volume to flow through.

At speed, water flows through a small inlet in the cone, which causes the shuttlecock to move rearward, causing a very slight constriction of the amount of water flowing through the thrust nozzle, which increases top end by about 1-2 MPH. This constriction also helps keep the pump loaded with water a little better than with an OEM cone, which helps with hook-up in choppy water.

I ran my boat the other day to test out the new impeller and wear ring. Got up to 39 MPH at around 8500 RPM, but couldn't go any more on the throttle due to porpoising. If I had a passenger in the front, it wouldn't do that. But I need to make some kind of adjustment to my ride plate so the porpoising isn't an issue. Also found that my thru-hull bearing for the driveshaft has a slight leak..... :x :x :x Not enough to sink the boat, but enough that I wouldn't leave it docked in the water overnight. At some point I have to deal with that, too...and removing that bearing is a real SOB.

 

[okavango]

The AAT cone does seem to make a difference in hole shot, and on top end. It uses a spring-loaded shuttlecock that moves back and forth, dependent on water flow through the pump. At low flows, the shuttlecock is retracted, allowing full water volume to flow through.

At speed, water flows through a small inlet in the cone, which causes the shuttlecock to move rearward, causing a very slight constriction of the amount of water flowing through the thrust nozzle, which increases top end by about 1-2 MPH. This constriction also helps keep the pump loaded with water a little better than with an OEM cone, which helps with hook-up in choppy water.

I ran my boat the other day to test out the new impeller and wear ring. Got up to 39 MPH at around 8500 RPM, but couldn't go any more on the throttle due to porpoising. If I had a passenger in the front, it wouldn't do that. But I need to make some kind of adjustment to my ride plate so the porpoising isn't an issue. Also found that my thru-hull bearing for the driveshaft has a slight leak..... :x :x :x Not enough to sink the boat, but enough that I wouldn't leave it docked in the water overnight. At some point I have to deal with that, too...and removing that bearing is a real SOB.

Thanks PSG, I like the idea of the AAT cone and will include one in my next order from the States.
As mentioned in the my build thread I induced porpoising when I adjusted the ride plate to try improve reverse, I was amazed how easily this was corrected by bending the trim tabs at the base of the transom, certainly an easy and cost effective way to eliminating porpoising.

 

[amk]

hows that ss wear ring paying off? I was considering getting an entire solas 144mm pump with ss ring and 12 vane stator if it would actually benefit me.

 

[PSG-1]

As much as it pains me to say it, I haven't been running my jet boat much this summer. :shock:
Performance with the new prop seems to be good, though.

I think the SS wear ring will finally 'pay off' in a couple of years, when I don't have to deal with the issue of corrosion causing the liner to swell, and having to replace the wear ring. Again, the price for the SS model is so close to the OEM, it makes perfect sense to go ahead and buy quality, and be done with it. As for the stainless pump/stator assembly....I would love to have one of those skat-trak magnum pumps with the 12 vane stator, but they want over a thousand dollars for it!!

 

[amk]

True I've found almost a $500 gap in prices between sites some have them 1500 and some 1100 but I will need a new pump soon and that pump is the same for 650, 701, 760, and 800 model yamahas so it's pretty diverse if I ever needed a new motor or scraped everything and wanted to sale. I just wonder if that pump would give me any performance improvements.

 

[PSG-1]

From my understanding, the 12 vane stator gives significant performance gains over the OEM model. And again, with me operating in saltwater a lot of the time, one of those pumps would be ideal, since it's made of stainless and would resist corrosion, not to mention less wear due to it being stainless and not cast aluminum.

I was doing some searching last night, and almost got my hopes up when I saw a yamaha 12 vane stator for about 500 dollars.....but it was a 144mm....... The 155mm is still about a thousand dollars.

 

[amk]

so you think that 12 vane stator would match up well with oem wear ring so I could buy in pieces?

 

[PSG-1]

As far as I know, these units are made to OEM spec bolt patterns, so, it should bolt right up to your wear ring. Another difference, besides being made of SS, is with the additional 6 vanes, which help straighten out the turbulence. I think the vanes also have a little more 'kick' to their leading and trailing edges to help with this.

 

[amk]

I asked a jetski guru the 12 vane is better for bottom end pop but will shed a little top end. For top end a bigger impeller pitch is the way to go if it can turn it.

 

[bellman]

I asked a jetski guru the 12 vane is better for bottom end pop but will shed a little top end. For top end a bigger impeller pitch is the way to go if it can turn it.

I've been VERY involved in race gas, stroker, MSD, Skat pump, etc...standup jetskis for many years. IMO, the guy you talked to is mostly right. The only thing I'd disagree about is the top end loss. With the right prop, EVERYTHING is better with a mag pump. There are several variations. Vane count, size, and setback/non setback. By far the most common/desireable pump is the 12 vane setback. Setback pumps move the stator and prop rearward 1 inch, but require a setback shaft. This isn't much of an issue with jet Jon's since you're installing the pump assembly/cavity and motor mounts anywhere you want them. Between mid shafts and driveshaft lengths you can make almost any configuration work. Almost all yamahas use OEM 144mm pumps, with the exception of a few 760 sit downs and all of the larger motors. Interestingly, until you begin to make HUGE HP, nearly all 701/760 based boats use a 140mm mag pump in place of the stock 144. The stator vanes on a mag pump are stainless and can be be made thinner and straighten the water more gently, allowing for more nozzle exit velocity. There are a few "*******" 8 vane pumps out there and a fair number of 14 vane pumps, but most are 6 or 12. Either is so much better than stock that it is almost impossible to describe the difference. Think of John Force on his huge wrinkle race slicks compared to him running the same race car on cheap street tires. The difference is that great (especially as you increase power). The nice thing is that the trend in skis is HUGE(1500ish cc twins) motors that actually need bigger pumps. That means that there are far more 140's to be had on EBay for better prices. Even the 6 vane is VASTLY better than stock. With the 140, it requires the uses of a 140mm wear ring also. Skat bores the stock 144 wear ring and installs the smaller dia SS ring. The stator is installed the same way. SS stator installed in a bored stock stator housing. A used 140 will almost always come with the wear ring since it has to be used with that pump. They're also subject to corrosion issues, but the stainless ring breaks the aluminum, rather than the other way around as usual. The good thing is that Skat will install the wear ring or stator in another bored OE housing for about $100. If you happen to buy one new, the best thing to do is buy a chipped up stator and swollen wear ring and send it in to Skat to have your pump built. It'll save you several hundred dollars. I'm on the home stretch on a Tracker 15/42(?) jet Jon conversion (ill post pics when done) that's using a Skat setback 12 vane 140. Luckily I have 5 or 6 props to play with, but so far my experience is that you can run a much taller prop on a flat bottom Jon boat than you can on a ski. The Jon boat is a skipping stone almost the instant you touch the throttle so it's much easier to push. I've normally run a 13/19-21 on most of my skis (65 mph) but I'm starting out with at a 15/22 on this boat. The motor is just a stock 760, but will be running MSD total loss ignition, a bit more compression, a dried out stock pipe, and the mag pump. It should make a bit over 100 HP, so it's nothing crazy and can run on 50/50 AV gas/pump gas. With the right prop and nozzle diameter(stock is 81mm-most people bore the exit nozzle to 83-85mm) cavitation is a thing of the past and you'll be able to drive right through whitewater with no slip or spin. I'll see if i can get a few pics of the mag pump to post so the difference can be seen. Sorry for the dissertation, but a good mag pump setup is really almost too good to be true....except that it is. :lol: Hope that helps.

Charles

P.S. Regarding the all SS aftermarket wear ring, I'd personally buy a used OEM on EBay for next to nothing. They're a dime a dozen and usually really bad corrosion is associated with saltwater boats. I'd also personally stick with Skat props. Solas props are Chinese and use inferior stainless. That said, their mag pump copy isn't bad, but the base of knowledge for props, nozzles, etc. is far smaller.

 

[Jim]

Great thread gentlemen!

Learning a ton!

 

[CedarRiverScooter]

Me too!

Bellman - can you give any advice on Polaris 148MM Modular pump upgrades?