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  1. #1

    I can't get my 900 ZXI to start

    I bought a 900 ZXI that sank and I rebuilt the motor and fuel system. The first time I started it it ran well and then when I took it out to break it in it ran for 30 minutes, started bogging down, then died. I haven't been able to start it since and that was two months ago. It cranks but will not start. I have systematically gone through the entire ski and I feel like I know every part. I have tested compression and it is good across all cylinders, there is spark on each cylinder, and each cylinder is getting fuel. I installed a primer kit and it doesn't help. I checked the stator coils and they pass the resistance tests. I've replaced the CDI. I checked the kill switch and its good. My only thought is that the spark must either be weak or the timing is off. It seems unlikely, but both of the used voltage regulators I have don't seem to be passing the resistance tests. Could a faulty rectifier cause the ski not to start due to a weak spark? I need some opinions so I stop wasting money with no result.


  2. #2
    whats needed to run.

    1st is compression
    2nd is spark
    3rd is fuel

    as a quick test use an old/new plug thats for the engine, totally remove the electrode and test the spark with the modified spark plud held firmly against a known good ground,
    you should see the spark jump the gap to ground and it needs to be a medium/dark blue color

  3. #3
    This is how I run a jetski shop in the desert nmpeter's Avatar
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    sounds to me like the flywheel key sheared off...and with it your ignition timing is so far off that the engine can't fire at the right time.

  4. #4
    I'm starting to wonder. I don't know how it could be sheared since I just assembled the thing and I torqued it to spec. If I disassemble the exhaust to pull the engine, can I reuse the gaskets? Also, could the trim box have anything to do with this start issue?

  5. #5
    This is how I run a jetski shop in the desert nmpeter's Avatar
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    Quote Originally Posted by amecheng View Post
    I'm starting to wonder. I don't know how it could be sheared since I just assembled the thing and I torqued it to spec. If I disassemble the exhaust to pull the engine, can I reuse the gaskets? Also, could the trim box have anything to do with this start issue?

    don.t pull the engine yet.

    you have comprssion
    you seem to have spark and some fuel

    I.d try the mag plug lead on the other two cylinders to see if you get any signs of life.

    what did you do on the motor?

    any backfiring going on at any time?

    trim and regulator are not in play right now

    check the timing mark against tdc on the mag cylinder

    check the elctric box out (again) could have pinched a wire

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  7. #6
    I'm not sure what the "mag plug lead" is, is that the ignition wires? I'm pretty sure I have spark, I've removed the plugs and spark is visible. I've also used a timing light and a spark tester to confirm. The fuel looks good too. When I remove the plugs they are wet.
    When this ski sank it ingested sand into the motor and was started which scoured it. I rebuild it with new pistons, rings, hone job, seals, etc.
    It hasn't back fired. What would this indicate?
    The trim box works and I wouldn't think it plays a role in the ignition.
    "check the timing mark against tdc on the mag cylinder" how do I do this?
    I've gone through the electrical box several times and actually bought a second electrical box so I have back up components. I think it is good. I just ordered new oem ignition coils and a new rectifier. I should have the new stuff in a couple days so I'll see what happens.

  8. #7
    This is how I run a jetski shop in the desert nmpeter's Avatar
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    in mechanic spek the "mag" end of the engine is the end closest to the magneto..the pto is the one closest to the driveshaft. No backfire means the spark isn't firing at a time where there is enough fuel in the engine to ignite. checking the timing helps assure that the flywheel key hasn't sheared..it stinks to pull it apart to check it and find it's exactly on spec.

    With water ingestion you need to worry about a damaged crank seal and bent connecting rods. as the engine ingested sand..the whole thing should have been torn down to the bare crankcases as if there is any sand down there the engine is done.

    One tricky part of two strokes that mystify general mechanics is how everything can be "right" and the engine won't run. If you have fuel charge leaking between cylinders ( due to blown crank seals) you'll have what looks like good compression..but not enough fuel to fire it up.

    stop throwing parts at this problem and get back to basics. From your initial posts, the engine ran, so the coils and all the rest should be "ok"..bogging and no starts tend to be ignition related.

    get a shop manual which will describe how to check the ignition timing. A typical procedure would be to hook up the timing light on the mag plug lead and direct the strobe to the little plug on the stator cover ( which when removed can reveal the timing marks. You may want to find the mark and give it a good gouge with a center punch or pick so it's easier to see.

    your money pit is going to get real deep and replacing all parts is not an assurance of success. Only a methodical method is going to get you results and right now you need to determine if your ignition timing is right. The engine ran..so you need to look at an adjustment that isn't close to right .

    The alternative will involve pulling the engine to check the crankcases and crank bearings.

    Any gas spitting up from the carbs while you are cranking it?

  9. +1 by:


  10. #8
    The engine was totally taken apart. I built it from the bottom up. The only thing that wasn't rebuilt was the crank because I didn't have the tools to press it apart. As far as I remember the only seals on the crank where the front and rear seals.
    I didn't realize I could access timing marks with the little plastic plug but now that I know I will check the timing tomorrow.
    I haven't noticed gas shooting up when cranking it but I will watch for it.
    I own a "service manual" buts it's about the worst I have seen. Very little detail. I'm going to look for a better one.

  11. #9
    so you came to a party without any toys !

    you dont have a factory service manual ! But you rebuilt the engine ?

    you dont have any means of testing the ignition system other than it sparks !

    your confused about the trim system and how it doesnt relate to spark/ignition.

    you desire to throw parts at it !

    Ok, but a complete running ski and use it instead.

  12. #10
    Not sure the point of that thread. I do have a service manual but it doesn't have the procedure for testing timing. I believe it it the first edition. My ski sank and there was heavy corrosion on all of the electrical components so there is good reason to replace parts even if they do work. Plus I buy my parts on ebay at excellent prices so if I don't end up needing it I can sell it at little or no loss. My question about the trim system is valid considering how half of the wiring goes to it and for all I know there could be a faulty sensor causing the no start condition. I don't "desire" to throw parts at this. I bought this thing for $500 before summer as an empty hull with all the parts in boxes. After assembling it and only having 30 minutes of use the only thing I "desire" is to fill the hull with gasoline and light the thing on fire.

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