Page 1 of 2 1 2 LastLast
Results 1 to 10 of 17
  1. #1
    TopCop931's Avatar
    Join Date
    Apr 2010
    Location
    Nutley, NJ
    Posts
    520

    Can someone explain this to me once and for all?

    I wasn't going to start a new thread on this but I just don't get this and I need to get some clarification before I lose my freaking mind.

    I got the broken piece out of the stub shaft out of my 371 swirl impeller. As you can see in the pics below the impeller doesn't seem to have any damage other than some small burrs I removed from one blade. The splines and threads are in excellent shape. The outside of the blades are square and uniform. It isn't chewed up. It is the right part number. My wear ring is also in great shape, not even a scrape.

    Here is the big question: Why can I fit a 1/2" combination wrench between the blades and the wall of my wear (extension)ring? You can see that the 035 impeller is in there with a nice fit with less than .015 clearance. Is this swirl impeller supposed to go in there like that? I wouldn't think so. I realize I don't have it on the shaft like the 035 is but I should still be able to place it inside the ring and have snug fit while on top of a flat surface I would think.

    Click image for larger version. 

Name:	371 Impeller 004.jpg 
Views:	88 
Size:	57.7 KB 
ID:	206747Click image for larger version. 

Name:	371 Impeller 002.jpg 
Views:	72 
Size:	53.8 KB 
ID:	206746Click image for larger version. 

Name:	371 Impeller 007.jpg 
Views:	99 
Size:	93.0 KB 
ID:	206745Click image for larger version. 

Name:	371 Impeller 005.jpg 
Views:	78 
Size:	56.7 KB 
ID:	206744Click image for larger version. 

Name:	780 pump 004.jpg 
Views:	79 
Size:	67.0 KB 
ID:	206743


  2. #2
    bowsniper's Avatar
    Join Date
    Aug 2008
    Location
    macomb,michigan
    Posts
    5,896
    +1
    6
    measure the size of the prop. it should be 148mm.. they also make 146mm ones also. for example. I have a 8-vane stator with a small hub and its 146mm.. not 148mm like a stock stator..

    or the blades are bent from whatever went thru bending them.. other than that, I,m not sure..

  3. #3
    TopCop931's Avatar
    Join Date
    Apr 2010
    Location
    Nutley, NJ
    Posts
    520
    Quote Originally Posted by bowsniper View Post
    measure the size of the prop. it should be 148mm.. they also make 146mm ones also. for example. I have a 8-vane stator with a small hub and its 146mm.. not 148mm like a stock stator..

    or the blades are bent from whatever went thru bending them.. other than that, I,m not sure..
    I think if the blades were bent there would be some visible damage to the prop no? The blades should be chewed up a little I would think. The sides of all three blades are flat and even. I thought about the 146 mm thing but that impeller is a Polaris 5131371 swirl. It is the stock impeller that belongs in the thing. I could clearly see that this impeller was much smaller than the 5131035 that is in my other pump, but I figured that was because that one has 4 blades. Also it was on the same size stator Tom. 148mm. Polaris # REV 02 5630475.


    This is like alien, UFO sh*t.

  4. #4
    TopCop931's Avatar
    Join Date
    Apr 2010
    Location
    Nutley, NJ
    Posts
    520
    I thought I would entertain the thought of the blades being bent so I just quickly put it up on a flat surface and marked the ends of the blades as a measurement guide. All the points are the same. The blades are not bent, unless they all bent back evenly. I don't have a metric ruler so I couldn't measure it to see if it was 148mm but it has to be because it is the stock impeller.

    Click image for larger version. 

Name:	371 Impeller 009.jpg 
Views:	73 
Size:	39.1 KB 
ID:	206766Click image for larger version. 

Name:	371 Impeller 011.jpg 
Views:	59 
Size:	36.3 KB 
ID:	206767
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	371 Impeller 010.jpg 
Views:	75 
Size:	36.8 KB 
ID:	206765  

  5. #5
    Moderator beerdart's Avatar
    Join Date
    Aug 2006
    Location
    CT
    Posts
    25,930
    +1
    1,407
    The impeller was cut to 146mm? to run in a smaller wear ring? It is an odd ball. What is the ID of the wear ring?

  6. #6
    TopCop931's Avatar
    Join Date
    Apr 2010
    Location
    Nutley, NJ
    Posts
    520
    Quote Originally Posted by beerdart View Post
    The impeller was cut to 146mm? to run in a smaller wear ring? It is an odd ball. What is the ID of the wear ring?
    To cap off my day I just broke the dial indicator on my caliper so it looks to be just over 5 3/4" which is probably 148mm. (How do you guys measure the impeller diameter? I can't get my caliper across because of the high point on the impeller. Can you take the measurement from the bottom?) The thing is, that wear ring pictured above was in my ski with this impeller before the stub shaft broke. I was running good for awhile before this incident. Wouldn't I have had cavitation in my pump with this setup in there from the first time I put it in the water?

    You're right. Someone had this stock 5131371 impeller brought down to 146mm. The box that it came in said it was 148mm. I found it in the storage compartment with the old impeller in it when I got the ski. Whoever changed it must not have known what they were doing. When I was trying to check the clearance through the intake grate a couple of months ago I didn't know what the hell I was doing either. Again, a perfect example that you need to check everything out thoroughly. More than one person here told me to pull the pump and I didn't listen. Could this have also contributed to my drive shaft run-out also?

    Pictured below is the same extension on the 5131035 impeller that is definitely 148mm. which proves your point. Tom was right also. I just can't believe that it ran well at all setup like that.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	780 pump 004.jpg 
Views:	76 
Size:	67.0 KB 
ID:	206769  

  7. #7
    ph2ocraft's Avatar
    Join Date
    Apr 2006
    Location
    Campbell, Ca.
    Posts
    14,100
    +1
    105
    Just think about how much better it's going to feel once it's corrected.

  8. #8
    TopCop931's Avatar
    Join Date
    Apr 2010
    Location
    Nutley, NJ
    Posts
    520
    Quote Originally Posted by ph2ocraft View Post
    Just think about how much better it's going to feel once it's corrected.
    Tell me about it. I was running around 50 mph and didn't feel any cavitation at all until I made that turn and BOOM. I had over 4 hours on it before anything happened. I can't believe it. The bad news is that I have to go into pocket again for another impeller. That 035 will work but my rpms are going to be higher at WOT with it on there. There was someone in the classifieds that said he had an 079 which would work better for me, and he needed a 035 but I think he got one already. I wanted to swap. I will most likely have to get an aftermarket prop because nobody has the 371. Or at least I can't find one right now.

  9. #9
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    Location
    near Toronto, Canada
    Posts
    36,593
    +1
    1,275
    Quote Originally Posted by TopCop931 View Post
    ...That 035 will work but my rpms are going to be higher at WOT with it on there...
    Maybe not. If your engine is down just a few HP from stock, then the RPM with the 035 might be really close to optimal.

    One way to eke a little more speed out of a slightly worn engine is to under-prop it slightly, to allow to RPM to get into the engine's sweet zone despite the HP deficiency.

    Now that you know how to remove and re-install the jet pump, it won't take long to install and try the 035. You just might like it

    BTW, you can measure impeller diameter across the bottom. Or put the impeller between two parallel edges, then lift it out and measure the gap.

    Note: Not only were the original 1992-1993 non-modular Polaris jet pumps using a 146mm size impeller, but there were also some unusual racing jet pump configurations that used different diameter impellers.

    The Polaris Octane stand-up model uses a 144mm jet pump.

    The easiest way for a racer to get a smaller diameter impeller would be to take a 148mm prop of the desired pitch, and have it ground down to the diameter they needed. The blades may also have been bent (tweaked) to create the exact pitch needed for their application.

  10. #10
    TopCop931's Avatar
    Join Date
    Apr 2010
    Location
    Nutley, NJ
    Posts
    520
    Quote Originally Posted by K447 View Post
    Maybe not. If your engine is down just a few HP from stock, then the RPM with the 035 might be really close to optimal.

    One way to eke a little more speed out of a slightly worn engine is to under-prop it slightly, to allow to RPM to get into the engine's sweet zone despite the HP deficiency.

    Now that you know how to remove and re-install the jet pump, it won't take long to install and try the 035. You just might like it

    BTW, you can measure impeller diameter across the bottom. Or put the impeller between two parallel edges, then lift it out and measure the gap.
    I was a little iffy on the 035 after our discussion last night. I am not so sure I want to push this old girl more than she already has been. I figured the higher rpms may just have me in the pocket for another problem. You can see that the 035 I have is in great shape. I am still going to build two pumps so I guess I will leave the 035 in one of them. I am now looking at a Solas PB-SC-X. I am trying to learn more about them. Apparently the pitch is made with casting rather than bending. What are the pros and cons to that?

    I was going to try and measure that damn thing from the bottom and then I dropped my caliper and broke the damn thing. I have had it since 1983 anyway it was time for a new digital jammy.

    It just hit me. If I run the 035 I could be on the water tomorrow. I already have a new drive shaft and that pump is all ready to go.

    I am going to take your advice and try it out first. It is better than sitting around the house waiting for UPS to deliver all my sh*t.

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Hard starts...once and for all....
    By nmpeter in forum Kawasaki PWC Performance (2-stroke)
    Replies: 60
    Last Post: 04-19-2017, 06:05 PM
  2. Replies: 0
    Last Post: 06-12-2016, 01:25 AM
  3. Replies: 3
    Last Post: 11-19-2010, 08:51 AM
  4. Can someone explain this to me once and for all?
    By TopCop931 in forum Polaris Open Discussion
    Replies: 0
    Last Post: 07-23-2010, 06:10 PM
  5. Can someone explain this to me?????
    By Therock in forum 4-Tec Performance
    Replies: 15
    Last Post: 06-30-2005, 01:49 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •