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  1. #1

    Kawasaki 15F with a twist! Will not start.

    Hi Gents, for the twist, the engine is installed in a hovercraft. I have recently acquired the craft and am trying to make sense of how this has been put together. To start with, it has a new battery, Camshaft Sensor, Plugs, Fuel Filter. Fuel pump pickup was cleaned, and pump is working giving 45psi to the fuel rail. I drained old fuel out of the fuel rail. I put a test lamp onto the primary of the coils, and have power when cranking. Resistance check of the coils, and crank sensor are within specs. Likewise the injector plugs have power when cranking. Each injector was tested and their solenoids click when power is applied. Fuel appears to be getting into the cylinders. When attempting to start, the exhaust blows smoke rings, and I might get the odd pop but the engine will not run. A lot of the plug connections were dodgy and needed a good cleanup.
    I am not sure what to check next, and realise this is a bit of a tricky one. I suppose the fact that I am getting power to fuel system, coils and injectors is a good thing, but where to go from here? Any advice would be greatly appreciated.


  2. #2
    My name is Sean and I am addicted to STXs smokeysevin's Avatar
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    Neat, post up some pictures!

    Check the starter button and make sure that it meets the specs in the manual.

    Also do a check for spark on each plug by pulling the plug and grounding the plug threads to the valve cover bolts, then crank the engine over for a few seconds.

    Has the motor ever been rebuilt or modified?

    Sean

  3. #3
    Sean, thanks for the reply. When it was installed they put all the Kawaski gauges and controls into it. They didnt totally remove the old wiring, which has been a bit confusing. The starter button is turning over the engine, is there some other function it should have that I havent thought of? As far as I am aware the engine hasnt been touched, and was installed by a professional mechanic shop so I was told. Previous owner ran out of money and never got it out of the shop. Thats how I ended up picking it up. It was a performance shop that put the engine in, so I am confident that it was done right, and I cant imagine them putting in a dud engine. At this stage I just want to get it running and tackle any other issues after that. Once I hear it running, good or bad, I will be happy. Tried to get a video but couldnt load it up. Here is a pic of the machine itself. Tested spark today and it got confusing quickly. What was sparking is no longer. I was swapping plugs and leads but in the end it wouldnt the plugs wouldnt spark. It was very random at the first test. Started to think I had bad plugs or leads but they tested ok. Went back to the coils for power and they were ok. Tested resistance again and the primary resistance was 4.4 and 4.8 which is double what the book says they should be. Now looking for replacement coils. Does that sound feasable to you??? Cheers and many thanks, getting a bit closer to the problem.
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  5. #4
    This is how I run a jetski shop in the desert nmpeter's Avatar
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    just for grins, switch the plug wires around to see if a basic mistake was made

    some pics of this craft would be a nice distraction...

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  7. #5
    steve45's Avatar
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    Did they keep the wrist lanyard or bypass it?

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  9. #6
    My name is Sean and I am addicted to STXs smokeysevin's Avatar
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    I was thinking the same thing Steve but since I re-read the post and reply(talking about smoke rings), I am thinking Pete may have gotten it right with swapped coil leads.

    Sean

  10. #7
    Pete, Steve, and Sean, you guys were quick, I just modified my previous post and came back and you all had commented. The wiring was marked for the coils so I took it they were in the right spot. In saying that the fact that the resistance of the coils is so close I wouldnt be surprised if they were off the old engine. The spark had me chasing my tails for 20 minutes, and at the end of it, I was back to where I started. The coils seem to be the main unknown at the moment. I made up a test lead to check the gap spark, but couldnt get anything out of it. Being on my own its a bit difficult to hit the starter and see everything thats going on at the back of the craft. I believe I am on the right track, as long as you guys agree the coils are not correct.

  11. #8
    Quote Originally Posted by steve45 View Post
    Did they keep the wrist lanyard or bypass it?

    They kept the lanyard, and the kill switch works. Will not let it turn over if the lanyard is not attached.

  12. #9
    This is how I run a jetski shop in the desert nmpeter's Avatar
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    great pic,thanks, frankly I like a craft with a name

    so if the secret lies with Bonnie (groan)....

    plugs on high compression engines often spark like mad while out of the engine, but get snuffed when dealing with 200 psi.

    try a set of brand new plugs

    smoke rings indicate firing, but so far off time that you won't get even a wimper of real ignition..just the smoke

    this was a major transplant, all to easy to make a schoolboy mistake labeling all those connectors

    you really have nothing to lose here, because frankly speaking anything else is going to be painful to deal with

    of course the tax on this help will be a short video of that main fan running...I love stuff like this.

    A local has some sort of hovercraft in town with a 787 seadoo engine in it. it's bleaching in the sun and he won't entertain any thought of selling it, even though weeds are consuming it.

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  14. #10
    Quote Originally Posted by nmpeter View Post
    great pic,thanks, frankly I like a craft with a name

    so if the secret lies with Bonnie (groan)....

    plugs on high compression engines often spark like mad while out of the engine, but get snuffed when dealing with 200 psi.

    try a set of brand new plugs

    smoke rings indicate firing, but so far off time that you won't get even a wimper of real ignition..just the smoke

    this was a major transplant, all to easy to make a schoolboy mistake labeling all those connectors

    you really have nothing to lose here, because frankly speaking anything else is going to be painful to deal with

    of course the tax on this help will be a short video of that main fan running...I love stuff like this.

    A local has some sort of hovercraft in town with a 787 seadoo engine in it. it's bleaching in the sun and he won't entertain any thought of selling it, even though weeds are consuming it.

    I just went and swapped over the coil plugs. It didnt like it, it was struggling to turn over. I put them back to where they were and noticed that the plugs had been marked at some time to match their sockets.
    The plugs that are in it are new. I measured resistance throught them and they were all pretty well the same. The leads test ok as well. For me it points to coils OR 3 out of the new 4 spark plugs are shot. The coils measure 4.4 and 4.8 ohms on the primary and 15k on the secondary. Will that be out of spec enough to mess things up? I agree with what you were saying about the smoke rings. It occasionally give a good pop, but not a run of cylinders firing. It may well be only one plug is good.

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