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  1. #1
    madtom's Avatar
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    think i have a injector stuck 03 12f and water in the hull

    Hi all,

    Just got my 900 stx back up and running and was able to spend some time today working on the 03 12f. got the rear hull plugs replaced and was able to start it....


    Pretty sure I will need to go thru the injectors and clean it all up probably replace the fuel filter also.


    Symptoms:
    good spark
    will not idle reliably
    Smell of raw fuel in engine compartment....no visible leaks all fuel lines good no fuel dampness around any connectors.
    smell of raw fuel in exhaust.... and slick hitting the water
    checked temps of injectors while engine was running with infrared
    #1 81
    #2 80
    #3 80
    #4 66

    Fuel pressure running about 8 PSI low. I have a Adjustable FPR on the return line and everything was running about 43-44PSI when it was put up for winter.


    more to follow.
    Last edited by madtom; 06-01-2020 at 07:28 AM.

  2. #2
    madtom's Avatar
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    Today's update,

    I was able to pull the fuel rail. I taped the injectors in water bottles. When I hooked battery up and turned power on the pump built up pressure in the lines and #4 was like a garden sprayer. disconnected power and removed the rail completely.

    While I was in the compartment I pulled all electrical connectors apart and sprayed them clean and then reassembled. I have them strapped up high so that if there is another water leak the connectors will stay dry.

    Used fuel rail and injectors should be at post office tomorrow. I already have injector rebuild kit to put new filters and o rings in. I plan on putting new plugs in also once I get it running straight.

    I am surprised it even ran at all when I test drove and diagnosed it over the last few weeks.... Didn't say it ran well just that it ran. I learn something new every day.

    The water leak was caused by the water box to exhaust connector coming loose and leaking due to all of the raw fuel in the exhaust. I replaced the thin hose clamps that were on there with T bolt hose clamps and they are much better at clamping. No more leaks.

  3. #3
    madtom's Avatar
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    Today's update,

    Was able to get injector orings installed and the new to me fuel rail back in. I adjusted the FPR to 43-45 at idle.

    Test rode it around the bay for about 30 minutes... Ski is back in business. 54 mph GPS on my phone. I am still trying to find a slow water drip leak from one of the lines or fittings. only like a quart to half gallon in the hull after 30 minute ride..... much less water than before the new clamps over the exhaust.... there was like a couple gallons in the hull after that ride.

    So far I have checked

    1. driveshaft bearing seals are dry so not from there, lines coming in from the pump are good.

    After I pull the Output cover lines around the crank and redo the ends. I will test again.....

    after that my plan is to...

    1. Going to re run all the cooling lines to see if one of the ends has deteriorated.

    2. next will probably end up pulling the exhaust to check for cracks in manifolds.

    May end up replacing all the cooling lines.. Could be the waterbox the 4 into 1 or the manifold.... still hoping it is a fitting... oil cooler, intake side and exhaust side of block water line connections are dry so not there....

    Annoying as hell not as there is not really room to feel around and cant really get a view of where the water is coming from.
    Last edited by madtom; 05-02-2020 at 05:44 PM.

  4. #4
    This is how I run a jetski shop in the desert nmpeter's Avatar
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    there is a pesky piston ring like affair on the exhaust coupler 43058 , yours is likely stuck in the grooves and water will seep by it, could also be a leak from fiting 52014 which is hard to see in any case

    it's a huge pain to deal with. be careful, the sealing rings are brittle, googles advised

    parts diagram:

    http://partsfinder.onlinemicrofiche....asakipwc&a=168

  5. #5
    madtom's Avatar
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    Thanks,

    i will look at those fittings. thanks. those rings are probably gone. Has any ever used a high temp silicone rtv to help fill up the spaces around the rings when installing? It would be a pain to get apart but probably sealed until the next time you take it apart.

    Hoping that it is something simple but it will always be the last thing I check lol.

  6. #6
    This is how I run a jetski shop in the desert nmpeter's Avatar
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    not suggested.
    the two stainless rings are used there for a specific purpose. silicon would hold up for five minutes tops

    painful?

    very

    wanna do it twice?

    doubtful

    very hard to spot a leak there with the engine running

    its an infamous spot on the f series 4 bangers

    the pipe may also need some tig welding if its rotted thru from corrosion

    see other threads on repair of this area

  7. #7
    madtom's Avatar
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    Todays update,

    got to really dig into it and start to pull components out. A potential source of the leak was caused by a failing hose going to the cylinder head. completely rotted in some places. looks like i will now have to pull the intake side to get to the fitting on the head. it wasn't leaking enough at idle or part throttle when water pressure is low but was leaking at full throttle.

    I have all the parts and new cooling hoses to run, just will take me a few days to pull apart and then put back together again.
    Last edited by madtom; 06-01-2020 at 07:39 AM.

  8. #8

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    I second the piston ring on the end of the exhaust pipe piece. I had to order a new one and also put new rings in place, and also cleaned the mating surface really well in the waterbox outlet. That seemed to fix any leak issues I had.. Also, that pipe on the head under the intake love to rot away with the old design they had. The new one is much more robust and has a brass barbed fitting for the hose.

    Be sure to replace those spark plugs as soon as you can because they are so dainty and love to cause issues.. Also, ONLY use a torque wrench on them. I know it seems silly especially since we all think, myself included that we have a torque wrench built into our hands but it's critical that one be used and torqued to spec. Also, use antiseize on the threads.

    Good luck, keep the updates coming.

  9. #9
    madtom's Avatar
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    Todays update,

    All new cooling lines installed, new 4 into one and lower hour waterbox (18 hours lol) installed with new piston rings in the exhaust fitting. New blue connector installed.... old one had rust discoloration and a bell shape in the middle. I got everything back together and functional... everything runs but still some water getting into the hull. I can find no leaks from the lines that I can see.

    4 into 1 had some pinholes in the bottom and at the divider on the inside where the 4 exhaust tubes merge, and the waterbox inner tube was like swiss cheese.

    The cooling flow has the lines connected like the late 2003 12fs and exhaust temps have dropped 15 degrees from last year and it is running 90-92 degrees right now at the water box with 78 degree river water. So I did solve some issues there.

    new fuel filter.... some weird stuff was coming out of the old one... definitely needed it.

    I even broke down and found a replacement dashmeter for $600. now the dreamometer is back in operation and its not too bad it says 56-57 at full speed.

    I replaced all the cooling lines to include the flush and pisser lines.

    I am probably replacing the thru hull driveline bearing fitting next if I can find no leaks in the hull.

    My troubleshooting plan is to fill the hull with water tomorrow to see where it is coming out from. I think if it has a leak at the bearing fitting once it gets water to above the shaft/hull bearing fitting it may start dripping. I am thinking there is not enough pressure at idle speeds to flex the rubber around the bearing. It is only 2 years old but who knows how long it sat on a shelf. it looked dry around the bolt holes but I plan on looking everywhere to see if I can spot any locations where I missed something

    I am going to double check the thru hull fittings to the pump to make sure they are not cracked as I had this problem on the 900stx last year and I ended up just replacing it with a new pipe thru the hull. Frustrating to be so close to fully operational and still getting water in the hull.

    It seems like less is getting in but still 1-2 inches in the hull after 15 minute ride. Its coming from somewhere, now to continue to narrow the sources down.

    Was wondering if there were any problem areas that anyone knows of on the early 12f hulls? This was a early build as it originally had the oil cooler behind the engine block when I first got it. Both the oil cooler and Stator fitting were corroded and clogged. pipe on head was updated to newest version with brass fitting. All of those problems areas were replaced last year with updated parts. Going to double check all places where there is a thru hull fitting. So far this year I have replaced the exhaust thru hull gaskets and placed new drain ports into the hull.


    Plan on plugging along till I solve this issue
    Last edited by madtom; 06-01-2020 at 08:03 PM.

  10. #10

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    Filling the hull is a good idea, that's how I found the leak coming from the bearing housing rubber. Maybe also consider putting a GoPro(or knock off) camera with alight and ride around a bit. I've found some leaks that way too that would only show up under high pressures.


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