Yamaha Jet pump all-stainless wear ring assembly

[PSG-1]

Bellman explained it better than I ever could!

BTW, welcome to the board! 8)

 

[bellman]

Me too!

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

Polaris are a bit of a weird kind of boat. They made some REALLY good boats and some REALLY bad boats. Actually, I should say that about their motors. I've only worked on a few Polaris boats and they were all 650 & 750 triples. They made really good power for the cc's, but had a number of issues. The biggest problem I've always heard/seen with a lot of their triples is the crank isn't welded and it's so long that it's prone to getting out of phase. A buddy burned several holes in one cylinder's pistons before he got a trued and welded crank. I've got a little experience with the Octane standup which was built as an out of the box race boat. It's a twin that came with a good pipe, mag pump, etc. Was pretty successful in the stock class. The only only thing I remember about the pump in the SL 650/750 was that the pump was better than normal for an OE pump and the way it mounted in the pump tunnel was well thought out and was not likely to leak and suck air/cavitate the way a lot of Yamaha and Kawasaki pump mounts can. Sadly, almost no one works on Polaris (even Polaris dealers) and there aren't many people that know much about performance upgrades for them. He'll kill me for sending you to him, :? but Randy (formerly Watcon-sold business) was very involved with the Polaris factory racing effort back in the day and could probably give you the answer you need. He's the last of the good guys and probably has more Polaris knowledge than anyone alive. I'll PM you his info. Another VERY good source for parts and info is Jetworks. They've been around forever and have always built my motors. I'm an assembler/tuner; not the grinder/cutter. They're no BS and won't ever sell you something you don't need. Impeccable integrity. 949-548-5259. Definitely say Charles told you to call. They have extensive knowledge of every brand of PWC.

Charles

 

[CedarRiverScooter]

Thanks much! I have the 750 Fuji (blue) engine, rebuilt the fuel system, & it has run great all summer. The pump has eaten rocks & could use some love.

 

[amk]

Thanks for that post that's exactly what this forum is for.

 

[bellman]

Thanks much! I have the 750 Fuji (blue) engine, rebuilt the fuel system, & it has run great all summer. The pump has eaten rocks & could use some love.

With all my skis I've always been fanatical about rinsing out the pump after beaching and have managed to keep my pumps and props really mint. The jet Jon will mainly be a bow fishing boat also used for bass fishing. Luckily the rivers I bow fish are rivers I've paddled for years and most of the gravelly stuff that eats pumps is avoidable. The whole jet project is a result of what bow fishing under dams in giant rocks does to 1979 20 HP Mercury motors. [-X I also opted for trim instead of reverse so I can keep the bow above the water in wave trains in rapids. It's a cool story, but I can tell you for sure what happens if you let your bow get swamped with about $4000 worth of bows, rods, tackle, etc with you. It involves a lot of swimming and is a funnier story later than it is at the time.

 

[amk]

I have the yamaha 760 so your saying go from the oem 144 to a mag 140? Skat offers a 144 mag. And your also saying get the set back?

 

[bellman]

I have the yamaha 760 so your saying go from the oem 144 to a mag 140? Skat offers a 144 mag. And your also saying get the set back?

I always used 140's, but was curious about how a 144 would work. A friend of mine was sponsored so I was able to get a complete setback 12v with Skat driveshaft for a bit under 1G. After playing with it for a summer, we all agreed that it worked about the same as the 140. Our base of knowledge (props) for the 140 was so much better and between us we have so many different prop/nozzle/cone options to try I decided to sell it and stick with the 140. I'm sure I could have gotten the 144 to work a bit better than it did, but I would have spent hundreds trying different props to get there. A 144 prop for a stock pump doesn't work in a mag pump so it would have been expensive. Props can be repitched, with good results, but most of Skat's props start with different castings, so you can only do so much. You can't repitch the root of a prop so if you repitch a 13/19 to a 14/21 you may not have the same thing that you would if that's what you started with. They usually have about three different castings for each pump size. Not many builders know this (a good thing 8)). Mine always made sure to order props from a specific casting and then he tweaked until they were right. They frequently aren't exactly dead on out of the box. That said, we're talking about jon boats with stock hp and the ultra fine details aren't going to pay the same dividends. These boats started with 70hp and were in the 140-160hp range when finished so every slight detail could make a big difference. From my experience, it takes a LOT of motor to need more than the 140. I'd also get the non-setback because the stator housing uses the same bearing and shaft set as a stock pump. The setback uses one double row bearing in the housing and it takes some minor machining to make an OE shaft fit. For ease of making it all as simple as possible, I'd look for a used non-setback, although I wouldn't hesitate to grab a setback if the price was right. I would Also gladly take a 6, 8, or 14 vane. Any of them are so much better than the stock pump. Whatever you do, DON'T buy anything weird like a one off 147. You'll chase your tail forever trying to get it to work. Just be prepared to do a bit of work (for a setback) if the driveshaft it comes with isn't the right length for your project.

Charles

 

[amk]

So with a 140 I can run the same intake right. I don't have to change what's pictured?

 

[bellman]

So with a 140 I can run the same intake right. I don't have to change what's pictured?

You shouldn't have to change anything. Essentially, if you have a boat that an OEM Yamaha 144 pump bolts into, a Skat pump made to be used in place of the OE 144 will bolt in with no mods needed. Even the setback version bolts in directly. It just requires a 1" longer driveshaft. Normally a setback would be ordered with a shaft for the ski model it's to be used with so it's a simple pump swap. The Skat made shaft for the setback is a good bit more money than just installing your stock shaft into a non-setback. For the Yamaha Superjet (yamaha's stand up ski) a stock driveshaft for a Yam Blaster is the same length as the setback shaft for a Superjet. Some guys have bought cheap aftermarket blaster shafts and machined them to work in a sj instead of buying the Skat shaft. The other simple option is to use a mid shaft from another yamaha that will give you the needed overall length. That only applies if you used the OEM midshaft housing to connect your motor to the pump. If I'm not mistaken, Atlantic Jet Sports has all the yamaha drveshaft and midshaft lengths listed on their website so you can find a combo that will work. It all sounds really complex, but it's really pretty straight forward basic mechanic stuff. Hope that makes sense??? :?

Charles

 

[PSG-1]

opcorn:

Bellman definitely has a wealth of info about PWC's! This is the kind of info that you won't find in manuals.

 

[bellman]

I'll do my best to get pics of the mag pump and pics of an OE stator so the HUGE differences can be seen. It may not come out with great detail since the exit, steering, and trim are installed, but I'll see what I can do. A mag pump is truly a thing of beauty.

 

[bellman]

OK, I finally got around to taking the best pics of my pump/prop/rideplate/intake grate setup that i could. It also shows the steering and trim system. I also took a couple of pics of a stock stator section so the differences can be seen. Keep in mind The pictures of the mag pump are taken through the exit and steering nozzles from the rear because I'm far too lazy to take it out just for a few pics. Hope this makes all this easier to visualize. This is a setback 12 vane 140mm. Notice the short length & very gentle curve of the vanes. The stock stator vanes almost look like the letter j compared. There is also a considerable amount of tuning done at Skat after casting where every vane is shaped and all flash and obstructions are cleaned up. It's design is much more efficient because the water is not forced to make such sharp bends and it also is passing over thinner, more hydrodynamic vanes than impede water flow much less.

Charles

P.S. You can also see the rideplate I made. It's 1/4" al and is about 2" longer than the transom and nozzle. I've found myself floating backwards into rocks many times and it would crack the steering nozzle into a million pieces if the nozzle hit first. This should take the brunt of those hits. It's mounted with an inch thick piece of super hard rubber between it and the pump tunnel so it can absorb some shock and not disturb any adhesives.

 

[amk]

ya your stock looks ruff but nothing close to min I think most of my vanes are bent and chiped I guess I need to drop some cash on a mag pump.

 

[PSG-1]

There is definitely a noticeable difference in the configuration of the vanes of the OEM pump vs. the 12 vane. I feel pretty sure my boat would see some appreciable gains in performance with one of those. Just gotta save up the cash to get one.

 

[bellman]

Here's a link to the Riva pump strainer. It's made for 155mm pumps, but I think you could either adapt/fabricate a standoff to make it work on the 144 pump or make something similar.

https://rivaracing.com/i-17284030

P.S. That's the 90deg brass barbed fitting I mentioned in the dual cooling post. If you do add one, make sure it's perpendicular to the pump, not at any angle, so the water is forced into the cooling line. You don't want to make a low pressure venturi like the bilge fitting.

Charles

 

[amk]

Well I pulled the trigger on the stator it's a Solas came with new ss skat prop the shaft is fx1 I have to swap it. Unfortunately it'll be until mid December for trial run I wiped a crank bearing. I don't know if it's coincidence or I did it but i put seafoam in my gas and let it idle in the yard on the hose for about 20 minutes and all the sudden it messed up bad. Once I get it running it will be a beast.

 

[bellman]

Well I pulled the trigger on the stator it's a Solas came with new ss skat prop the shaft is fx1 I have to swap it. Unfortunately it'll be until mid December for trial run I wiped a crank bearing. I don't know if it's coincidence or I did it but i put seafoam in my gas and let it idle in the yard on the hose for about 20 minutes and all the sudden it messed up bad. Once I get it running it will be a beast.

That looks good! I presume it's a 144 since that looks like an OE wear ring??? If it uses props that fit OE pumps (unlike Skat pumps that require magnum props), you should be able to find one that's right on for your boat. If the prop is right for an FX-1, it may be shallow for your boat, but I'd definitely run it and see what sort of RPM you're turning before you do anything else. You can also change things a good bit with exit nozzle sizes. IMO, don't let anyone tell you to have the prop "cut back". Those pumps have more than enough hook up w/o it and it would likely hurt performance. When you get it dialed in, I think you're going to to blown away by what it's capable of. You really do have to see it to believe it. Having it in your hands, it's a thing of beauty isn't it! :beer: If you need any help with changing shafts or prop/shaft tools, etc. just PM me and I'll try to give you a hand.

Charles

 

[amk]

Thanks. This thing is 20lbs its noticeably heavier than the stock kinda thinking I need to have some angle welded back to bolt to the wear ring and exit nozzle bolt holes for support. I just checked its not a skat its a Solas 12/18 I think the same as I already have. Paid $650 for it shipped not an outstanding deal but definetly got it cheaper then new. The stator is $500 new then add the bearing and wear ring and new ss prop probably 1-1.2k new.

 

[bellman]

Is that the way your pump is setup when everything is all installed?

 

[amk]

Yes and it's worked great for over a year.