I just installed a hooker 9/15 on my 701 SN Superjet. I previously had an old Skat Trak 4/7 impeller, from what I've read this is an old aftermarket impeller made in the early-mid 90's. Worked well in the mid range but seemed to be lacking on the bottom end. I went to a 9/15 and have noticed zero significant improvement in the bottom end. If anything, I feel like it hooks up less. Its a stock motor with Ada head (190 psi), riva red pipe, and an aftermarket single screen intake. The prop doesn't feel like its cavitating, it just doesn't have the low end punch I was expecting. Do you guys think its slipping or something? Should I change the cone out in the jet pump (currently stock cone). From reading all the reviews of this impeller, I expected a noticeable difference and as of now its been disappointing. Let me know your thoughts. Thanks.
Hooker 9/15 Slipping?
- Thread starter Th3 VVay
- Start date
- Location
- Great Pacific Northwest
I ran a hooker 9/15 in my old SN, that was stock other than a B pipe, and it def hooked up better than stock props and was a huge improvement. I think you have something else going on. Such as cavitation from air leak (when you took pump apart to install 9/15 did you use silicone?) especially more specifically on the rubber that meets wear ring to pump shoe.
No silicone was used on the pump shoe/seal. I do have a brand new pump seal I can install, although the existing seal looked in pretty good shape. Would silicone be required with a new seal? I didnt even remove the old seal. Just unscrewed the skat trak and replaced it with a hooker. Again it was already an aftermarket impeller, albeit a much older design. So maybe I wouldn't get as much improvement as expected?
- Location
- Lake Orion, MI
what size reduction nozzle and cone? is the engine reving out? 9/15 should be nice for your setup...did you verify pitch with a gauge?
It has an ocean pro steering nozzle (the one that's splits the flow with the vertical bar down the center) that's the same as the reduction nozzle correct? I'm not sure what size they are, it's more of an oval shape than round. Has the stock cone in pump and no I did not verify pitch with a gauge. Is there a sticky somewhere on how to do that?
- Location
- Saskatchewan
MY 9/15 made a huge difference, check your wear rear tolerance with a feeler gauge
- Location
- Long Island
Your old prop was probably a 14/17. On a stock pump, ive had good results using a 12/17 small hub skat trak impeller. The reduction nozzle is the first piece that bolts to the back of your pump. Your steering nozzle(ocean pro) is not your reduction nozzle.
A 9/15 impros "hooker" isn't gonna turn your 701 into an arm ripper. They work better than a stock worn out prop. That's the performance gain most people 'feel' and claim its the bomb after that....
Shine a flashlight through your intake grate and look into the back of your pump. You should be able to slide a piece of paper between the prop and wear ring. if you can slide 10+ pieces of paper between the blades and wear ring your prop has too much clearance.
A 9/15 impros "hooker" isn't gonna turn your 701 into an arm ripper. They work better than a stock worn out prop. That's the performance gain most people 'feel' and claim its the bomb after that....
Shine a flashlight through your intake grate and look into the back of your pump. You should be able to slide a piece of paper between the prop and wear ring. if you can slide 10+ pieces of paper between the blades and wear ring your prop has too much clearance.
- Location
- Ontario, Canada
It should be noted that the Hooker, Skat-Trak C75 series freeride and Solas Concord YQ-CD impellers are all large hub impellers. Although they can be used in stock pumps, they are not going to perform as well as they are capable of. They should be installed into either a mag pump built having a 75mm hub design or at least run in a stock pump with a pump core stuffer (typically referred to as a pump stuffer). With the stuffer installed, the pump will pressurize much more in accordance with the impeller's intended design. The stainless aftermarket replacement impellers for stock applications will quite possibly perform better than the large hub impellers due to the smaller hub, the blades are larger capturing more water and the impeller is designed to work in that arrangement. Putting a large hub impeller into a stock pump will potentially result in losing performance because where there was the extra blade surface to capture the water, there is now just a straight surface for the water to pass over. For lack of a better term, the water is essentially going "fall off of" the trailing edge of the hub as it now becomes a raised ledge, the water will not have the constant straight surface to maintain the higher pressure the large hub impeller is trying to produce which in turn will drop the pump pressure and volume. If you want that 9/15 Hooker to really perform, at the very least consider locating a pump stuffer. They are not cheap though, as far as I know right now there are only 3 options available, R&D, TBM and Blowsion...but the Blowsion stuffer is identical to the R&D, just a different anodized color. Here are a few links that show what they look like...
R&D - http://www.rd-performance.com/newProducts/yamaha/superjet.asp
TBM - http://tbmracing.com/web/components...ge/product/TBM_Racing_Yamah_4a49bca5b27fa.jpg
Blowsion - https://www.blowsion.com/products/pump-handling/pump-cones/superjet-thrust-force-pump-corehub-kit
R&D - http://www.rd-performance.com/newProducts/yamaha/superjet.asp
TBM - http://tbmracing.com/web/components...ge/product/TBM_Racing_Yamah_4a49bca5b27fa.jpg
Blowsion - https://www.blowsion.com/products/pump-handling/pump-cones/superjet-thrust-force-pump-corehub-kit
- Location
- Chicago
Pro-pulsion while I agree big hub impellers will perform to their best potential with a matching pump hub diameter, we have personally seen gains on a few skis from a small hub to a big hub, all else equal.
Latest was last summer on my 550/800 (then 750) with the Rhaas pump swap kit. I tried a 13/18 small hub, 13/18 c75 big hub, and 10/16 hooker impellers. Low end progressively increased. The 10/16 had the most bottom end, and allowed the engine to rev out the most for the highest gps speed.
I think it's a bit more complex. Impeller blade surface and hub size also is closely related to the hp / torque of an engine and what it can pull. Hull wetted surface area and ski weight also factor in.
Its clear that from a flow perspective you will see a gain from a matched pump hub. Just want people to know you can definitely see gains without it. That's one thing I hope to test this summer on my ski and I will post up my impressions somewhere.
Latest was last summer on my 550/800 (then 750) with the Rhaas pump swap kit. I tried a 13/18 small hub, 13/18 c75 big hub, and 10/16 hooker impellers. Low end progressively increased. The 10/16 had the most bottom end, and allowed the engine to rev out the most for the highest gps speed.
I think it's a bit more complex. Impeller blade surface and hub size also is closely related to the hp / torque of an engine and what it can pull. Hull wetted surface area and ski weight also factor in.
Its clear that from a flow perspective you will see a gain from a matched pump hub. Just want people to know you can definitely see gains without it. That's one thing I hope to test this summer on my ski and I will post up my impressions somewhere.
Thanks for the input guys. To answer a couple questions asked. It is the standard stock bore reduction nozzle. I just checked wear ring clearance with my feeler gauge and it's right around .5mm or .02" I believe that is slightly out of spec? Would that be enough to get some cavitation? If so, why didn't I notice it on the skat trak? The skat trak was the old 14/17 but it felt better on the bottom than the hooker. I don't expect it to be an arm ripper, but I would expect more snap down low than what the skat provided. Do you guys think I need a new wear ring? It still has the stock stainless one but I'm pretty sure it's been a fresh water ski it's whole life and it looks in good shape minus being on the line tolerance wise.
- Location
- Ontario, Canada
It wouldn't be a bad idea to have a fresh wear ring on hand just because. The stock wear ring has a stainless sleeve and sometimes with fresh water wear rings...and very often with salt water wear rings...the aluminum body will corrode between the sleeve and swell. This will impact the stainless sleeve against the impeller and either make the impeller scrub or lock it up totally. I just went through this with a Blaster 1 I have been working on. I ended up ordering an SBT wear ring from JetManiac with the replaceable liner. This will be nice because the liner will take the abuse and save the impeller. In your case, it would seem that the impeller is wearing down. If it was used a lot around sand beaches then that will wear down the impeller. It always seems that the impellers on Yamaha pumps will wear out first which is odd as stainless is not a hard metal, it will take damage very easily but yet the hardened stainless impellers always take the beating, and much much more so with the OEM aluminum impellers.
- Location
- Ontario, Canada
The last option then before looking to replace the wear ring is to replace the pump seal. That impeller should actually spin up a lot faster than the Skat you had on there due to it's much lower pitch. The way to tell if your impeller is cavitating or not is to try and pay attention to your jet stream. When you are at low speeds, just past idle to keep you standing, quickly go to full throttle for 2-3 seconds, that will be long enough to get the impeller really spinning but not long enough to get you fully planed out. Try to pay close attention to the bubble trail...if the bubbles are coming up looking somewhat large, say from the size of a marble and up to golf ball sizes, then you are boiling the water which is severe cavitation. If the bubble trail is more like millions of little bubbles like a carbonated sody pop, then there is no cavitation. The point here is to determine if your pump seal should be replaced or not...that would be where I would put attention into now. You have a new wear ring, you just need to install it yeah? If you install it anyway just for good measure you might find it to be a bit of a pain to compress where you can seat your pump onto the alignment pins...that will mean it is going to seal. If the old one will allow the pump to just slip into place with no compression needed, then it probably should be replaced. My ski went through this too and I thought the same about my seal. It looked to be in good shape but when thinking about it, they are an expendable item and do wear out, and mine was the original one from 1996, I think 20 years of service permits it to be retired lol. They probably will not last as long as they once did too when you start hopping up your ski's performance. It is just that much more thrust they have to deal with.
- Location
- Winter Haven, FL
Did you use any washers behind the impeller?
If nothing rubs, run no washers. I had better hookup after removing the washers/spacers behind the impeller and installing a pump stuffer (not sure what helped more though...).
If nothing rubs, run no washers. I had better hookup after removing the washers/spacers behind the impeller and installing a pump stuffer (not sure what helped more though...).
You probably had better hookup from the pump suffer, not from removing the washer. I don't want to get into a $400 pump stuffer right now. I know this prop should be performing better based on others reviews of it so I just need to figure out why its not hooking up how it should.
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
if your wear ring is worn, your other prop did not move as much water so you probably did not notice much loss. The newer swirl props are designed to load the pump more aggressively. With this new prop you may be showing the issue of too much clearance.
I like this theory, that makes a lot of sense. Does anyone know the correct specs for wear ring clearance? I guess what should it be on a stock "new" wear ring and then what is the allowable limit?
- Location
- Ontario, Canada
Impeller clearance limit 0.6mm or 0.024" according to the book, any clearance less than that and it's good.
- Location
- Michigan
+1 on the pump seal. I was recently having horrible cavitation issues and bought a new pump seal. Fixed the problem completely.
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Yeah I have a new seal I'm gonna throw on today when I reinstall the pump, but the existing seal looks pretty fresh. Slight curling on one section of the seal but way better than the seal on my waveblaster. That seal is basically just the metal band and it doesn't cavitate at all lol. It's weird though but I guess I don't know what light cavitation feels like. I had the stock pump shoe crack on my waveblaster and it would barely move. The superjet takes off just fine, but like I said, it's not pulling how I would expect. Anyhow, I'll do the seal today and make sure everything is siliconed well and see if I notice any change.