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Thread: 3 Stage Jets. Impeller Pitch, Nozzles and other upgrades

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    Default 3 Stage Jets. Impeller Pitch, Nozzles and other upgrades

    There was some interest in a discussion on my last post about Impeller pitch for my Extra Plus load testing. It was suggested that I start a new thread.

    Here is what I have found out, but sources vary. The most consistent answer is "see what happens and go from there".

    Set-up: Kodiak 3 stage, Kodiak 351, 20.5 Xtraplus with 60" bottom.

    I had 3 worn but functional brass impellers. Standard 19deg for all three. Kodiak (KEM) suggests that the biggest gain to be made for the 350 type motor is to change out the rear impeller for a 24degree and change the intake grate. The intake grate has wider slats to let in more water, but will let in bigger rocks too. I was convinced not to put that in by everybody I talked to about it. I talked to Professional Marine, and Mike had all sorts of good suggestions. It came down to money in the end, and I opted for the KEM suggested upgrades as well as their posinosle at 92mm. I only had to buy one impeller and I filed down two of the 19's to knock the burrs off. I noticed a big difference in the boat handling immediately with the posinosle. The old T3 nozzle is junk. I think my hole shot is better now and I am running about 100 RPM less. Not bad.

    Then, I called Schlagel Marine in Boise, a Scott Jet dealer. I actually tried to call Scott Jet in New Zealand, but they did not pick up the phone. It was worth the money for the phone call just to listen to their accent on the answering machine. Schlagel Marine was incredibly helpful as well. He we adamant that upgrading to a progressive pitch system and increasing my nozzle size would absolute improve my load handling ability again as much as just the KEM suggested upgrade. He did some sort of calculation, or looked into the magic eight ball, or something and suggested the overlap impeller for the front at 19deg, the middle at 22 degrees and the rear at 24 degrees. He also suggested increasing the nozzle size to 100mm with their posinosle. You can change the diameter with an insert for $50-60.

    This is were the discussion could get interesting. What kind of snake oil did I get sold. Kodiak or Scott. The whole idea is to increase torque and push more water for increased load handling at lower RPM's. I believe the KEM/Kodiak upgrade achieved this. We will see about the Scott. I am sure it will too, I am hoping that it is 200-300 RPM lower that when this boat was stock. That could be some big fuel savings when going down the yukon a couple of times for Mooseys. I bet there are some opinions out there on this. I would love a good explanation on how changing the pitch works too. There you go AKboater80

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    Quote Originally Posted by Daved View Post
    There was some interest in a discussion on my last post about Impeller pitch for my Extra Plus load testing. It was suggested that I start a new thread.

    Here is what I have found out, but sources vary. The most consistent answer is "see what happens and go from there".

    Set-up: Kodiak 3 stage, Kodiak 351, 20.5 Xtraplus with 60" bottom.

    I had 3 worn but functional brass impellers. Standard 19deg for all three. Kodiak (KEM) suggests that the biggest gain to be made for the 350 type motor is to change out the rear impeller for a 24degree and change the intake grate. The intake grate has wider slats to let in more water, but will let in bigger rocks too. I was convinced not to put that in by everybody I talked to about it. I talked to Professional Marine, and Mike had all sorts of good suggestions. It came down to money in the end, and I opted for the KEM suggested upgrades as well as their posinosle at 92mm. I only had to buy one impeller and I filed down two of the 19's to knock the burrs off. I noticed a big difference in the boat handling immediately with the posinosle. The old T3 nozzle is junk. I think my hole shot is better now and I am running about 100 RPM less. Not bad.

    Then, I called Schlagel Marine in Boise, a Scott Jet dealer. I actually tried to call Scott Jet in New Zealand, but they did not pick up the phone. It was worth the money for the phone call just to listen to their accent on the answering machine. Schlagel Marine was incredibly helpful as well. He we adamant that upgrading to a progressive pitch system and increasing my nozzle size would absolute improve my load handling ability again as much as just the KEM suggested upgrade. He did some sort of calculation, or looked into the magic eight ball, or something and suggested the overlap impeller for the front at 19deg, the middle at 22 degrees and the rear at 24 degrees. He also suggested increasing the nozzle size to 100mm with their posinosle. You can change the diameter with an insert for $50-60.

    This is were the discussion could get interesting. What kind of snake oil did I get sold. Kodiak or Scott. The whole idea is to increase torque and push more water for increased load handling at lower RPM's. I believe the KEM/Kodiak upgrade achieved this. We will see about the Scott. I am sure it will too, I am hoping that it is 200-300 RPM lower that when this boat was stock. That could be some big fuel savings when going down the yukon a couple of times for Mooseys. I bet there are some opinions out there on this. I would love a good explanation on how changing the pitch works too. There you go AKboater80
    A good combination for impellers in a 3 stage depending on elevation is a S1XL overlap 23 followed by a 24 with a 100 mm nozzle insert. We just converted a 773 with this impeller combination using an insertable Flo Pro posi-nozzle 100mm it pulled 4200 wot with an impressive hole shot. HJ 212 are running 108mm nozzles giving them a very good hole shot and load packing capabilities.

    Claude:

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    Just to clarify. The overlap (XL), then the 23, then the 24? Who's overlap impeller, yours, scott or KEM? Thanks. I have looked at your sight, nice boats.

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    Daved I am very interested in seeing your results since this is the same situation I am in. My Wooly came with three 23's in it and I quickly ate them up with a case of my head being up my you know what. So I had them rebuilt, then dropped a Scott overlap upfront then a 22 and a 23. Holeshot was better but cruise rpm seemed to go up 100-200 rpm. Mine also has a 92mm posi nozzle. I thought about getting the adjustable nozzle and playing with inserts and other impellers but have not gotten there. A part of me just wants to pick up a used Hamilton 212 and drop it in. In the long run I think it will be cheaper than the 3 stage and it is well known for its load carrying capacity which is what I am after. I would love to get my cruise rpms down to 3200-3400 and wot to 4200 and can care less about the speed. Saving fuel and getting more weight on step is what I want.

    Mine is a 22 foot Wooly Sportstour, hard top, full camper canvas, 330 HP Chevy 350, and a Kodiak 3 stage.

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    Bronco,
    Just curious what kind of weight does your boat pack now when you load it up with the Scott bullet and 3stage?
    V2d

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    Sounds like you are really close to what I have, except I am running an older 351, probably about 260HP. It runs strong, good compression, just not hopped up like they are now a days. I am very interested in what you happens if you change your nozzle. Let us know if you do.

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    Quote Originally Posted by Vsquared View Post
    Bronco,
    Just curious what kind of weight does your boat pack now when you load it up with the Scott bullet and 3stage?
    V2d
    I have no idea. I normally head out with 150 gallons of fuel, 3 teenagers, 1 wife, the dog, all my fishing crap, plus hunting crap because you never know what you will run into, food, extra clothing, sleeping bags, stove, 1 gallon of stove fuel, some misc tools, extra parts for the boat, hip waders for everyone on board, water and soda pop. One of these days I need to weigh all of that and see what it comes out to. With that load it does not have any problems getting on step and staying on step but my rpms are at 3700 and I am going approx 28 mph.

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    Quote Originally Posted by Daved View Post
    There was some interest in a discussion on my last post about Impeller pitch for my Extra Plus load testing. It was suggested that I start a new thread.

    Here is what I have found out, but sources vary. The most consistent answer is "see what happens and go from there".

    Set-up: Kodiak 3 stage, Kodiak 351, 20.5 Xtraplus with 60" bottom.

    I had 3 worn but functional brass impellers. Standard 19deg for all three. Kodiak (KEM) suggests that the biggest gain to be made for the 350 type motor is to change out the rear impeller for a 24degree and change the intake grate. The intake grate has wider slats to let in more water, but will let in bigger rocks too. I was convinced not to put that in by everybody I talked to about it. I talked to Professional Marine, and Mike had all sorts of good suggestions. It came down to money in the end, and I opted for the KEM suggested upgrades as well as their posinosle at 92mm. I only had to buy one impeller and I filed down two of the 19's to knock the burrs off. I noticed a big difference in the boat handling immediately with the posinosle. The old T3 nozzle is junk. I think my hole shot is better now and I am running about 100 RPM less. Not bad.

    Then, I called Schlagel Marine in Boise, a Scott Jet dealer. I actually tried to call Scott Jet in New Zealand, but they did not pick up the phone. It was worth the money for the phone call just to listen to their accent on the answering machine. Schlagel Marine was incredibly helpful as well. He we adamant that upgrading to a progressive pitch system and increasing my nozzle size would absolute improve my load handling ability again as much as just the KEM suggested upgrade. He did some sort of calculation, or looked into the magic eight ball, or something and suggested the overlap impeller for the front at 19deg, the middle at 22 degrees and the rear at 24 degrees. He also suggested increasing the nozzle size to 100mm with their posinosle. You can change the diameter with an insert for $50-60.

    This is were the discussion could get interesting. What kind of snake oil did I get sold. Kodiak or Scott. The whole idea is to increase torque and push more water for increased load handling at lower RPM's. I believe the KEM/Kodiak upgrade achieved this. We will see about the Scott. I am sure it will too, I am hoping that it is 200-300 RPM lower that when this boat was stock. That could be some big fuel savings when going down the yukon a couple of times for Mooseys. I bet there are some opinions out there on this. I would love a good explanation on how changing the pitch works too. There you go AKboater80
    So I went and started a new thread and then found this.... Thanks! I am still missing how you can from a 19-24 (or anything courser for that matter) To me it seems a 19 will only pull in so much water, wont a 22 or 24 spinning the same rpm require more water?

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    I am not sure on the physics either. Fuzzy math.

    I have an update on rep pitching and upgrading for the do it yourselfer. I took apart the jet again, no prob. Then put the bullet impeller in. It fit a little tight, so I put another key in and made sure it was all clean. Here is one of the mistakes. I hit it a few times with a hammer. Bad idea. The Scott bullet impeller is now firmly stuck on the main shaft of the jet drive. I shifted the seal on the jet housing trying to lever it out. Not sure if I smashed up the main bearings as well. I brought in to Professional marine to have the experts fix my goof up. They will try and give me insights as to what went wrong. Was it a me problem, key problem, shaft or impeller. Best case scenario, I will have shop labor costs to have them use their tools and expertise to remove the impeller, change the rear seal and check the main bearing (as able). I may have to have the shaft removed to allow them to use a press to get the impeller off. That usually involves picking the motor up with a hoist to disengage the linkage. I may now have shaft with a new scott impeller forever attached also. Who knows. The bill may be a few hundred to a few thousand dollars. Yep, gotta love boats. At least I don't have an airplane. As far as I know I still have a wife. Yet another big boat blunder, and that may be in question too.

    Mean while, I have no idea how these things work since I clustered it all up. Stay tuned......

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    Daved that sucks to hear, I hope you get your boat out of the shop without losing your shirt and wife. They are never cheap and some lessons are learned the hard expensive way!

    Sometimes you have to take a torch and heat the impeller up to get it to expand and then tap it off, or another technique is to attach a ratchet strap to it and then to your swim deck and start ratcheting it and see if it will come off or sue a combination of the ratchet strap, heat, and tapping on it.

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    That is my hope, they can just torch it, and use some leverage to get it off of there. None of which I have at home. Sometimes it is best to cut your losses and let the professionals do it. Come to think of it, if I was really into cutting my losses, my front yard would look a lot better with all the projects gone.

    I REALLY want to load test this thing to get my fuel consumption nailed down for planning fuel drops if needed.

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    Trials and tribulations - Been down this road as well with my old 22 foot inboard. After years and numerous changes I ended up with a 351W, Kodiak 3 Stage, overlap up front, 2 19's in rear, 92mm Kodiak posi nozzle. I added lots of weight to the boat over the years with items like the hard top and we carry big loads so when rebuild time came around we stroked the old 351 to a 393 with high torque in the specific power band we needed. Gathering as much (limited and conflicting) information as I could I swapped the 19 pitch impellers for 21's.

    Moving forward - motor only turned at 37 RPM's and was not utilizing the full power band and struggled with a really heavy load. Needing more RPM's I finally made the call to Flo Pro looking for a bigger nozzle but they didn't have anything in stock they could help me with - (Preparing for a moose hunt so waiting was not an option). Next call was to Schlagel Marine for a Scott Nozzle with the adjustable nozzle size (change inserts) which arrived 4 days later. Opted for the 100mm and put it on the boat and gained 100 RPM's - While I was hoping for more, 100 rpm's was a lot when it came to performance - in that range of the power band it was a significant power increase.

    Back to the drawing board - The motor was still not running like we felt it should - Went with a new and larger carb and headed to the river only to have the boat run worse - (huge sigh of disgust here) Pulled over to the side of the river scratched our heads stared at the motor (with look of despair) and then swapped the 2 plug wires we had stuck on the wrong cylinders.

    Turned the key with an immediate response, smooth idle, (big grin and huge feeling of stupidity here). Nailed the throttle and the V8 came to life, both seats rolled over backwards, the bow boy almost went out the back, on step in a few feet and turned 4200 RPM's. Only problem slight miss on top when holding it wide open - needs new fuel filter.

    The boats load was very light at this point and I don't have good numbers under a load but I was able to run 30MPH at 9 GPH in that short river test and I haven't seen numbers like that in a long time. The boat planes the best at 30MPH and I am not sure what to expect for fuel consumption to maintain that speed with a heavy load (over 2500 pounds). Heading to the Koyukuk in 9 days so it will be put to the test and lots of time to study the performance. Hoping this is where all the work and dollars finally come together.

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    Quote Originally Posted by Daved View Post
    That is my hope, they can just torch it, and use some leverage to get it off of there. None of which I have at home. Sometimes it is best to cut your losses and let the professionals do it. Come to think of it, if I was really into cutting my losses, my front yard would look a lot better with all the projects gone.

    I REALLY want to load test this thing to get my fuel consumption nailed down for planning fuel drops if needed.
    It's never a good idea to tap on the impellers on or off. Hopefully they are successful.

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    And so the story goes....

    The guys at Professional Marine managed to remove my bullet impeller without damage. Leverage is a wonderful thing.

    I Finally found the time to load test my boat today and it is no different, maybe a bit worse actually by 200 pounds. Max RPM about the same at 4-4.1k. Barely stays on step at 3.5k RPM. Into the secondaries at 3.6. At the very least I am right back where I started from, but without the bronze impellers. And of course over a grand of my pocket.

    My hope is that the nozzle size is too big. I plan on calling Schlagel Marine Tuesday AM to see what they think. Maybe a new insert will slick things up a bit. I a rapidly running out of time to dilly dally with this. I leave in a week for the Yukon.

    Any thoughts?

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    What degree impellers are you currently running and what size nozzle? Sorry a bit confused with all your post.

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    NOW: 19 degree scott overlap, 22 deg scott, 24 KEM. 100mm nozzle. Older 351 estimated 260HP.

    WAS: 19 degree stock bronze, 19 degree stock bronze, 24 degree KEM. 94mm nozzle.

    Stock: 19's and the T3 nozzle. Both the above have a big improvement over the stock set-up.

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    Daved,
    To bad it will take some more tweaking. Hopefully nozzle adjustments work. Don;t overlook the carb tweaking as you are vey close. What carb do you have? If there is a way to delay the secondaries to say 3700rpm it might work. Depends on the type of carb, Professional Marine or Anchorage Drag Bike should be able to steer you in a good direction on the carb.
    What fuel flow did you get at 3600 with the secondaries part way open?

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    make sure your not sucking air from anywhere either, check the o-ring on the inspection hatch and that the air bleed hose is hooked up. a compression check on the motor might be a good idea aswell. I talked with schlagle marine awhile ago and thats exactly the same impeller/nozzle setup he reccomended for my 22' wooldridge with a 285hp 351. If your only turning 4-4100 max i would try dropping the nozzle size a bit and getting it back up to 44-4500 max. Did they say what shape your stators were in and what the tollerances were on your new impellers? Did you put in wear rings with the new impellers?

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    Quote Originally Posted by Daved View Post
    Just to clarify. The overlap (XL), then the 23, then the 24? Who's overlap impeller, yours, scott or KEM? Thanks. I have looked at your sight, nice boats.
    The combination of impellers was exactly what you said. This combination was powered by a 330hp 350. I don't think brands will make any difference unless your looking for durability. I would recommend a 19 overlap 19 & 23 with a 96mm nozzle insert. This should give you about 4200 wot and 3400 mid-range curise. You got to keep in mind your 260hp is rated @ 5800 to 6000 wot rpms. You need rpms to build torque and hp and by dropping down a nozzle size like mention with you current setup will not give you a performance increase besides dropping the rpms down more.

    Claude:

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    Claude and Aksparkey01, I think you are saying different things. Will decreasing my nozzle size to say 96mm increase or decrease my WOT RPM's? With increase RPM's I can then delay my secondaries opening to around 3700 RPM's and cruise at 3400-3600 and achieve more load capacity.

    Or, do I have the wrong impeller pitch? I have the stock 19's still, but they are a bit worn. I could do a 19 overlap (new), 19 bronze (old) and a 24 stainless (new) with either a 92 or 100 nozzle (both of which I have now). This is all quite confusing.

    I am not opposed to having a nozzle insert sent up pronto (like , but I really don't want to buy yet another impeller if I do not have to.

    To answer the other posts:
    All my rings are new and there is minimal wear on the wear rings. They were all replaced, but the impellers were not.

    Ya, a compression check would be in order, but it is too late now to really do anything about it. It seems to be running strong, no leaks, oil is good. I am going to roll with it.

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