Results 1 to 6 of 6
  1. #1

    GP12r - Does the drive line needing alignment?

    Not sure if theres an issue underlying, but this is the second time I thought something got sucked into the jet pump. After a fair amount of no-waking it, I noticed the driveline had a pretty nasty vibration getting out of the hole, until about 4000rpm. This time, I was a long way from a dock so I decided to just bare with it. I stopped the engine, restarted, and the problem still happened. It wasnt until I ran the RPMs way up the problem went away and things were smooth for the rest of the day from that point at all RPMs.

    Back at the house, and ever since I bought the ski; When idling on the hose with the seat off, I hear some clinking and clanking down by the driveline at idle. When reved up a bit everything goes silent. The engine shakes just a bit at idle, but in all runs fantastic on the water. Does all this sound normal? I dont hear any clanking when the seat is on or idling in water.

    I've had the stinger off before, and while I was there checked alignment. It felt pretty good by the feel of my hand.

    Could there be soemthing wrong with my ski's driveline?
    Eric


  2. #2
    steach's Avatar
    Join Date
    Dec 2005
    Location
    Rock Tavern, NY
    Posts
    3,174
    +1
    174
    Sounds like you got debris on the impeller both times. This is not uncommon to suck up small sticks and/or weeds.
    The high rmp's will usually force the junk to cut loose.

    I wouldn't be a bad idea to snatch the pump off and check the prop for damage and clearance with the wear ring, the condition of the shaft and splines as well as the condition of the pump bearings/grease.
    -when holding the shaft with the wear ring attached, the pump should spin freely with no rubs.
    (if you hear a rub take a close look at the lining of the wear ring. , the SS liner can pull away from the housing and bind the prop from corrosion between the SS and aluminum)

  3. #3
    Quote Originally Posted by steach View Post
    Sounds like you got debris on the impeller both times. This is not uncommon to suck up small sticks and/or weeds.
    The high rmp's will usually force the junk to cut loose.

    I wouldn't be a bad idea to snatch the pump off and check the prop for damage and clearance with the wear ring, the condition of the shaft and splines as well as the condition of the pump bearings/grease.
    -when holding the shaft with the wear ring attached, the pump should spin freely with no rubs.
    (if you hear a rub take a close look at the lining of the wear ring. , the SS liner can pull away from the housing and bind the prop from corrosion between the SS and aluminum)
    Thanks

    I agree that something may be getting sucked in every time; Prop from rear and under looks perfect from what I can tell without taking a bunch of stuff off. The wear rings also looks like its still new with ~0.5mm gap all the way around. I'm planning to get an upgraded prop someday soon so I'll wait before I disasemble the stock unit at this time.

    I was able to reach down and check the coupler again with my hand, and noticed the engine is about 1/16 of an inch lower than it probably should. I bet the motor mounts are starting to sag a bit. I was able to shim under both output-side motor mounts with two huge 1/16" thick washers and now the coupler alignment is much better than before. In doing this, I also found the stock shims presen but they weren't enough on their own. It could even use a little more centering by 1/32" left-to-right but that will have to wait until I can get the carbs out so I can better access 3~4 mounts. All mounts were re-secured with lock-tight. Also, it appeaars the motor in my unit was never removed from the hull - the bolts had factory locktite on them.

    Hopefully it will feel smoother out there.

  4. #4

    Join Date
    Jan 2006
    Location
    Texas City, Texas
    Posts
    1,249
    +1
    15
    You talked a lot about engine alignment. Did you check your pump alignment?

  5. #5
    Not sure I follow. Theres an faq on aligning the couplers by lossening mounts and dry cranking over the engine - where the engine seats itself centered after a few jolts. Is that what you mean? I dont think this procedure would have worked well for me since the engine was sitting to low - sounds more for left/right adjustments. I needed more shiming for lift.

    Otherwise, I dont know what you mean by pump alignment? I searched too.

  6. #6

    Join Date
    Jan 2006
    Location
    Texas City, Texas
    Posts
    1,249
    +1
    15
    Your original question was about a driveline alignment. There always seems to be lots of concern with engine alignment rather than the pump, probably because it is the engine that is removed and needs to be aligned more frequently. From the factory, many GPR's were known to have poor pump alignments. Since it is normally only set once, most do not think about it.

    You said that your engine was to low. Did you stop to think that maybe it was the intermediate shaft that was to high? Because the pump shaft is mated to the intermediate shaft, it is possible that the pump shaft is throwing the intermediate shaft out of alignment.

    The transom plate is the aluminum plate between the wear ring and the fiberglass hull. Look at the plate from the back of the boat and you will see 3 tabs located at the 11:00, 1:00, and 2:00 position. They ALL must be touching the fiberglass stops built into the hull. If not, then your pump is out of alignment.

    Symptoms of a bad pump alignment include:

    1. A loud clanging from the pump area when on the trailer during flushing.
    2. A worn wear ring, sometimes just on 1 side of the ring.
    3. Vibration on the throttle at certain rpms, but not always at all rpms.
    4. Wear on the edge of the impeller blades that come in contact with the wear ring.
    5. With time, a ruined intermediate shaft (splines distroyed)
    6. With time, the splines on the pump shaft are made sharp or pointed as opposed to being squared.
    7. Difficult for the pump to be removed and reinstalled (because the splines are not perfectly aligned).

    All of these symptoms are the same as a poor engine alignment. All I am saying is look at both of the drive train ends, then ask yourself if the engine were off by the same amount as my pump, would I be happy with it?

    My guess is that if your pump were aligned perfectly, then you would find that you need the stock motor mount shims back in to set the engine properly. Your pump should then slide in and out easily without any difficulty, and all of that clanginging and vibration should go away.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Does the 2015 FZS need an aftermarket intake grate?
    By OutlawGPR in forum Yamaha PWC Performance (4-stroke)
    Replies: 3
    Last Post: 02-14-2016, 10:57 AM
  2. How to remove the drive line coupling shaft???
    By kyle5647 in forum Yamaha PWC Performance (2-stroke)
    Replies: 1
    Last Post: 07-19-2013, 07:47 AM
  3. Does this drive shaft need to be replaced?
    By imp0ster in forum 4-Tec Performance
    Replies: 15
    Last Post: 01-25-2013, 08:19 AM
  4. How hot does the exhaust get, need some advice !!
    By Hondapro210 in forum 4-Tec Performance
    Replies: 5
    Last Post: 08-12-2011, 04:58 PM
  5. When towing a jet ski, does the cooling line need to be plugged?
    By sbklf in forum Kawasaki Open Discussion
    Replies: 4
    Last Post: 02-07-2011, 05:28 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
  •