Page 1 of 2 1 2 LastLast
Results 1 to 10 of 12
  1. #1

    Join Date
    Jan 2009
    Location
    Perth, Australia
    Posts
    8

    '03 Gp1300r loss of speed ... powervalves?

    About 5 years ago one of the power valves failed on my ski a week after it went into be serviced, they said the cylinders were covered really thick (too thick) with carbon (even though it was serviced the week before). Basically it was only reaching about 80-85km/h or so, and wouldn't reach the top end speed. This was found out because a guy I knew through his GPS into my ski and took it out, when it failed to reach the top end, he told me to take it back and get them to have a look. They ended up have the ski in the shop for a month before replacing the power valve that failed.

    Recently I got my ski up and running ago after leaving it sitting for a year without being used, (broke my arm wavejumping and took me quite a while to build up the muscles to control it again), took the plugs out, replaced them, sprayed lube down the cylinders, turned it over by hand etc, new battery, and started it up and it was the smoothest I have ever heard the engine.

    But the speedo (for as unreliable as I know they are) can only reach about 80km/h WOT, and from my feeling, there is no speed gain in the top ~1000-1500rpm which would indicate that the power valves are failing to work? I know most problems are associated with the power valves falling into the cylinder etc, but has anyone had experiance in a case like this?

    I have not GPS'ed the speed as I no longer have access to one, but I have had a mechanic (who built a superstock gpr) ride my ski and yeah, it is pretty slow. My brother and uncle are mechanics and we plan on converting the currently completely stock Gp1300r to somewhere near-superstock this June-August, still fine tuning what we would like to do. He said with a manual for the engine then he could take apart the power valves himself and have a look, but I have been unable to find a manual (not the operation's manual) for the Gp1300r.

    Is it worth taking a look, has anyone been able to fix a problem like this before? Or should I just take it into the shop and pay them?


  2. #2
    Moderator OsideBill's Avatar
    Join Date
    Mar 2006
    Location
    United States
    Posts
    11,875
    +1
    30
    If you are gaining RPM and no speed you have a pump or hull issue, look for something underneath dragging or impeller damage etc.

    Here is a link to the manuals http://www.mediafire.com/ServiceManuals

  3. #3
    "Hustler" Inkaddict's Avatar
    Join Date
    Aug 2007
    Location
    NJ
    Posts
    4,712
    +1
    26
    Since its an 03 (Pump tunnel recall) Id also pull the pump shoe and make sure your pump tunnel is still intact... Just a thought...

  4. #4
    Moderator OsideBill's Avatar
    Join Date
    Mar 2006
    Location
    United States
    Posts
    11,875
    +1
    30
    Good call TJ, that was the dreaded year for the pump tunnel.

  5. #5
    Just want to ride.
    Join Date
    Dec 2005
    Location
    Sumner, WA
    Posts
    413
    +1
    5

    Servo

    You can check to see if the powervalves are 'cycling' while the boat is on the trailer. Take the seat off, put the lanyard in, and hit the start button, then stop button. The power valve servo motor will cycle in about 10 or 15 seconds - you will see and hear it. If you look at the top of the motor, opposite the big exhaust pipe, you can see 2 cables that come to the end of the cylinder toward the back of the motor. Watch to see if the wheel they attach to moves back and forth, and then look between the cylinders to see if the little rubber boots move as well.

    If the motor is bad, nothing will happen, and that would explain your top end loss.

    If the motor works, and they are cycling, it's only a 10mm socket to remove the 4 bolts on top of each of the powervalves (the little rectangular covers just above where those rubber boot thingys are). You can take the covers off yourself (be careful, there's a gasket under there) and do the same process again. If the pin has come out of any of the powervalves, you should be able to tell by looking, and when the rocker turns, it will be pretty clear if there's a problem.

    You can do this part yourself - just be careful and patient, and within 10 or 15 minutes you can probably get your own answer about whether or not they are working or broken!

    Good luck
    Sean

  6. #6

    Join Date
    Jan 2009
    Location
    Perth, Australia
    Posts
    8
    I have never heard of the pump tunnel recall?

    I was going to send it in next week for the cable recall, but that is the only recall I ever heard of for my ski. There is nothing dragging underneath because I get down on my hands and knees and wash the underbelly every time after skiing, the last time I checked the prop was when we got the ski up and running and there were no major chips or visible damage done to the prop. I will take another look at the prop in the morning and check it again.

    The ski is about 100 hours old and completely stock, no work done what so ever.

    I gain a tiny bit of speed in the final RPM range, but not as much as I remember being able to, perhaps about 5km/h, say pushing it from 80 to 85.

    The pump will be reinforced and sealed, I was waiting for the Aussie dollar to get a bit stronger as importing things here is quite expensive at the moment compared to what it was a year ago, and I was going to import everything, from mats to heads in one go to save in shipping, but I am thinking now that maybe I should import the pump reinforcement kit/seal kit now and the rest later. But seeing it is completely stock I presume the tunnel should be fine? But I will take the pump shoe off next time I am at my brother's place, he has all the tools ... he has spent more on his tools than I have on my ski ...

    I presume (99% sure from common sense) that sealing the pump does not cause any hassle to changing the prop later on?

    And can you elaborate on the pump recall? I never heard of this before?

    I can't thank you enough for the link to the manual, that is going to be a great deal of help. That has really made my night

  7. #7

    Join Date
    Jan 2009
    Location
    Perth, Australia
    Posts
    8
    Quote Originally Posted by washingtonrider View Post
    If the motor is bad, nothing will happen, and that would explain your top end loss.
    If the wheel doesn't move, i.e. the motor is bad, is it just the power valves that will need replacing, ie, putting in Riva Gas power valves? or will the whole engine need to be rebuilt? I presume that replacing the power valves with gas valves would fix the problem? And would Gas be the way to go or should I go with YPVS? I was planning on replacing them either way when we do the ski up. I believe it should be about ~450US for the YPVS and ~600US for Gas.

    I will check that tomorrow morning, as it is midnight now and I don't have a light in the garage. I am more than willing to try anything myself, not really from a money point of view, but more, I like to understand how things work. I also thought the sound I heard after the ski was turned off was the bilge pump not the power valves, but I know what you are talking about, where the power valves are located and where to look.

    Thank you for the detailed explanation, I will be sure to tend to this as soon as I wake up, after breakfast of course

  8. #8
    philip_gpr's Avatar
    Join Date
    Dec 2005
    Location
    Canada
    Posts
    2,724
    +1
    3
    before you seal anything up you should take the ski to the dealer and get them to do the free pump shoe bracket recall

    good chance your problem is the servo motor as mentioned above

  9. #9
    philip_gpr's Avatar
    Join Date
    Dec 2005
    Location
    Canada
    Posts
    2,724
    +1
    3
    ...
    Attached Files Attached Files

  10. #10
    Just want to ride.
    Join Date
    Dec 2005
    Location
    Sumner, WA
    Posts
    413
    +1
    5

    Servo

    If the motor doesn't move the wheel, you have one of two problems - neither require a major rebuild.

    Either the servo motor is bad, which does happen, and can be replaced fairly quickly/cheaply with a used one (or new, if you don't mind paying extra), or there is an electrical problem to the servo motor (like the plug is bad, corroded, etc.); again, this might be the servo motor end of the plug, so you can just replace with a working one.

    My bet is you can fix this, IF it's the motor, for $50 or so with a used Servo motor.

    Of course, if it's not the servo motor/wiring, you're off in another direction entirely (like the Catalytic Converter being broken in the exhaust)....

    Good luck!
    Sean

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. loss of speed?
    By GREENSMACKER in forum Yamaha PWC Performance (2-stroke)
    Replies: 13
    Last Post: 04-05-2008, 09:22 AM
  2. Loss of speed
    By davesgpr in forum Yamaha PWC Performance (2-stroke)
    Replies: 3
    Last Post: 11-05-2006, 08:04 PM
  3. Loss of speed and High Rpms
    By njgprider in forum Yamaha PWC Performance (2-stroke)
    Replies: 8
    Last Post: 09-02-2006, 11:35 AM
  4. Loss of speed and RPMs
    By NJ-Ski in forum Sea Doo Open Discussion
    Replies: 11
    Last Post: 07-21-2006, 10:34 AM
  5. Jerry - Loss of rpm - loss of speed
    By RXPDAVID in forum 4-Tec Performance
    Replies: 5
    Last Post: 06-13-2005, 03:47 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
  •