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  1. #1

    03 GP1300R won't go over 30MPH 5000RPM

    Hi, I'm new to the forum, but have been finding a lot of great info on here. I'm hoping that maybe someone has experience with my problem and could offer some help. I've found similar posts, but nothing within the last few years on this topic.

    Ski information
    2003 GP1300R
    Fuel injected
    Power valves
    85 hours
    Low compression
    D Plate
    Oil block off

    My 2003 GP1300R is suffering from a lot of bog and hesitation. It will not rev passed 5,000 rpms while under load. At WOT I can hear the engine revving up and down and up and down like it's trying to get passed 5,000 rpms, but can't, so I'm only hitting around 30ish mph. Before this weekend, it was revving over 5,000 and hitting 66mph on the dash and 60 on my gps.

    The compression is low. 72psi, 65psi, 72psi. I checked compression earlier in the week though (right before this problem started) and it was 75psi, 69psi, 79psi. Yes, there's a slight drop in compression, but I'm also using a different compression gauge than earlier in the week. That leads me to believe compression isn't the issue. I also want to add that I know the compression is very low. They are within 10% of each other though, so it should run, and it was running.

    I've changed the plugs and verified they are sparking. I unscrewed the plugs and rested them on top of the cylinders, while they were still connected in the leads. I cranked the engine and could see spark jumping from the plugs. So I don't think spark is the issue.

    My problem began happening while riding outside the channel at high tide between the marsh. I thought maybe some debris was caught in the impeller or the intake. I reached inside the impeller while in the water and couldnt feel any blockage. Once I got on land and could inspect with a flashlight, there were a couple strands of seaweed hanging from the intake grate, but not a clump of it. I easily picked them off. I didn't go so far as to disassemble the intake or the impeller, just looking for debris with a flashlight. So I don't think waterflow is the issue.

    My next thought is bad fuel or a clogged injector, but I think a little more background is necessary first.

    This is my first jet ski. I bought it about a week ago from a guy in Connecticut where he ran it on a fresh water lake in the 4 years he owned it. I live on Long Island, NY and have used it in salt water the 3 times it's ran. When I bought it, there was a little bog in the bottom end, but could move passed that and get up to WOT (60mph). It was throwing fault code 54 for a malfunctioning stepping motor at the time I purchased it. When letting off the throttle, as I came down under 3,000rpms the code would trigger, but wouldn't effect performance. I brought it home and took the battery box, electrical box, and muffler assembly off in hopes of just cleaning the connection for the stepping motor with some electric cleaner. When I reached the stepping motor, I noticed it just wasn't plugged in for some reason. I cleaned the connection anyway, plugged it in and reassembled the ski. I brought it out again and ran it for 2 hours with no mechanical issues or fault codes, then my problem began, but it's not throwing codes.

    I've been checking the forums, and some threads suggested a clogged injector due to bad fuel. When I bought the ski it had about a half tank of gas and I didn't think to drain the tank. Previous owner said he'd used it a couple times this year but not much. His registration sticker expired in 2017, so who knows how old the gas was. I put 10 gallons of 93 octane and premixed yamalube 2w at 40:1 prior to the problem. After the problem started, I added fuel and injector cleaner to the fuel tank and burned about 2 gallons of gas. That didn't solve anything, but I assume if the problem is a clog, the cleaners wouldn't be strong enough to fix that.

    I saw another forum post that said it sounded like an exhaust leak. Now when I had taken it apart to get to the stepping motor, all I removed was the muffler which is just sealed by hose clamps at the exhaust joints. Although I haven't taken an exhaust system apart before, I don't think I could have sealed it poorly considering it ran fine for a few hours, but I'm not a mechanic.

    The previous owner seemed honest, but you never know. He said he didn't have any issues with the ski. However, its impossible that he wasn't at least getting fault code 54 considering the stepping motor was disconnected. He acted unaware of the problem. From what info I read on the forum, I believe the stepping motor regulates the throttle bodies at idle? Maybe he had it disconnected for a reason? I'm not sure if reconnecting it could have caused the issue I'm experiencing? But like I said, it did run fine for 2 hours. I tried disconnecting it again and running the ski, but the the bog and no top speed issue persisted.

    Sorry for the long post, but I feel like it's important to give as much information as possible. Does anyone have experience with an issue like this?

    If you think it's the injectors, can those be cleaned or do would I need new ones?
    If I cleaned or replaced the injectors and it's not that, what would be the next step?
    Should I check something else before assuming it's the injectors?
    Could there be something lodged in the intake even though I can't see it with my eye and a flashlight?

    Any and all advice you could give me would be much appreciated.
    Last edited by DylanT; 09-17-2018 at 05:03 PM.


  2. #2
    If you compression is that low your engine is toast!!
    should be 120

  3. #3
    My Jet Ski drinks more than yours Glenozzy's Avatar
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    try another gauge with a charged battery if it still reads low your toast , good news when you take off the head should be easy to find

  4. #4
    Quote Originally Posted by scittb View Post
    If you compression is that low your engine is toast!!
    should be 120
    Just as a follow up to my post, I know compression of a well working jug should be around 125. I understand the compression is very low, but they are within 10% of each other, so technically it should run, and it was running with compression this low. If you have other advice to offer, that'd be helpful. Thanks!

  5. #5
    Doesnt work that way. If the gauge is correct it doesnt matter if they are with in ten percent of each other. Compression is way to low to run or make power properly. The engine is done. Needs a rebuild. Your gonna do even more damage running it as is and your not even going to have a core left to wrok with!! Sorry for the bad News but theres no band aid for an engine with that low compression

  6. #6

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    Quote Originally Posted by DylanT View Post
    Just as a follow up to my post, I know compression of a well working jug should be around 125. I understand the compression is very low, but they are within 10% of each other, so technically it should run, and it was running with compression this low. If you have other advice to offer, that'd be helpful. Thanks!
    I agree with scittb. Technically it is running, just not at full power due to not having full compression. If your lucky it’s a set of pistons and back up and running without cylinder damage. Being that the power valve servo was unplugged would lend me to think maybe someone started to disassemble it and changed their mind for some reason. You are going to need three pistons at a minimum, popping the head off will help checking the upper parts of the cylinder for damage. Good luck.

  7. #7

    Join Date
    Sep 2018
    Location
    Parkersburg, WV
    Posts
    6
    I am also new to this forum but I was having the same problem with my 03 GPR. Had very poor acceleration and wouldn't go above 35mph(took forever for it to even get to that) Turned out that the 3rd cylinder was not firing due to a faulty fuel injector. Hope you get it figured out!

  8. #8
    Quote Originally Posted by Mekesterson93 View Post
    I am also new to this forum but I was having the same problem with my 03 GPR. Had very poor acceleration and wouldn't go above 35mph(took forever for it to even get to that) Turned out that the 3rd cylinder was not firing due to a faulty fuel injector. Hope you get it figured out!
    When you fixed your problem, did you do the work yourself or did you have it serviced? What did you check before you determined it was the injector? And was it possible to clean the injector or did you have to replace it entirely? Thanks

  9. #9
    Yes injectors can be cleaned. You have more issues than that. Dirty injectors may of caused your low compression but again theres no easy fix here. Your going to need piston/ring kits possibly renickasli the cylinders, possibly a new head and depends how yor crank and rod bearings look. New bottom end seals, and have to check your reeds. I have built many and still have a 1300 engine in my xlt. I know them very well! All in all a full engine build. No 1300 motor with that low of compression is just an easy fix.

  10. #10
    Quote Originally Posted by scittb View Post
    Yes injectors can be cleaned. You have more issues than that. Dirty injectors may of caused your low compression but again theres no easy fix here. Your going to need piston/ring kits possibly renickasli the cylinders, possibly a new head and depends how yor crank and rod bearings look. New bottom end seals, and have to check your reeds. I have built many and still have a 1300 engine in my xlt. I know them very well! All in all a full engine build. No 1300 motor with that low of compression is just an easy fix.
    No doubt is the compression way lower than what's acceptable and I don't doubt your knowledge of these engines. Definitely have more experience than I do with these. What I just don't understand is how the engine was running 60mph with this low of compression, then suddenly it can't hit over 30mph but there's been no more compression drop

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