Results 1 to 7 of 7
  1. #1

    How freely should the impeller spin?

    I've got a project ski going on, and I'm now installing my rebuilt jetpump. I've run into something that I'm not so sure about though. After tightening the impeller to the specified torque, how freely should this thing spin? I've got all new bearings, seals, o-rings, etc. This is between stator, stub, and impeller, unit is not connected to wear ring.

    Mine spins alright, however it's nothing that would spin on it's own. For example, once you stop pushing it the impeller stops immediately. It pushes with finger pressure, just not as easily as I would have expected. I have nothing for comparison as this jetpump was toast when I got it.


  2. #2
    Moderator beerdart's Avatar
    Join Date
    Aug 2006
    Location
    CT
    Posts
    25,929
    +1
    1,407
    With new bearings and seals it should spin smooth. The bearings are sealed and filled with grease. There will be some drag.. If it spins by hand and feels smooth you are good to go.

  3. #3
    10-4, thanks beerdart. Impeller doesn't make contact with stator, however it's very close. It spins smooth, just requires more force than I would have expected as there's a decent amount of drag. I suppose the drag comes from the contact between the spacer and grease seals, even though it's all greased up.

  4. #4
    Quick update: Ok problem solved, and it was operator error.

    The rear bearing wasn't completely seated by about 1mm. Instead of the spacer supporting the force, it seems to have put a side load on the inner races between the bearings. Fully seated the rear bearing, spacer sits snugly between the two, and the force trying to squeeze the bearings together is now properly supported by the spacer. Rookie move.

  5. #5
    Moderator beerdart's Avatar
    Join Date
    Aug 2006
    Location
    CT
    Posts
    25,929
    +1
    1,407
    Quote Originally Posted by mystahagy View Post
    Quick update: Ok problem solved, and it was operator error. (Remove and replace manual stick operator)and/or Pilot error??

    The rear bearing wasn't completely seated by about 1mm. Instead of the spacer supporting the force, it seems to have put a side load on the inner races between the bearings. Fully seated the rear bearing, spacer sits snugly between the two, and the force trying to squeeze the bearings together is now properly supported by the spacer. Rookie move.

  6. #6
    i have a 96 slt780 bored 2 mm over scoop grate hot seat muffler water box and vortex breathers, just ordered high performance ride plate.what would be the best impeller to run.ps right now i can almost run with frinends 1100 yamaha. thanks wayne

  7. #7
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
    Join Date
    Oct 2006
    Location
    Cleveland OH
    Posts
    17,328
    +1
    29
    What are you looking for, top speed or acceleration. I'm assuming top speed if you want to hang with the big boys, but you may lose some abilty to pull 3 people or a tube. If speed is what you want, send Jetskimn a PM. He does alot with Nu Jet impellers from what I hear.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. How hot should the fuji 780 get?
    By Un-cowJ in forum Polaris Open Discussion
    Replies: 6
    Last Post: 03-20-2014, 02:11 PM
  2. How quickly should the water separator fill???
    By oldskool in forum Polaris How To & FAQs
    Replies: 17
    Last Post: 08-22-2012, 07:17 AM
  3. How freely should a impeller/pump spin?
    By Chrisrokc in forum Yamaha PWC Performance (2-stroke)
    Replies: 16
    Last Post: 07-13-2008, 01:23 PM
  4. How rough should the idle be?
    By Rio Vista in forum Yamaha Open Discussion
    Replies: 5
    Last Post: 03-13-2007, 01:33 PM
  5. How many mm's is the impeller alen bolt on the prop?
    By Jeff C in forum Sea Doo Open Discussion
    Replies: 6
    Last Post: 09-22-2005, 09:40 AM

Posting Permissions

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