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  1. #1

    Seadoo 717 engine crankcase oil line

    Does anyone know what regulates / limits the oil flow on the oil line connected to the crankcase from the oil tank on the 717 engine? I have a 97 seadoo sportster that is blowing a lot of oil out the exhaust when it is running. It seems to be running okay so I don't think it is a problem with the oil injection pump. Any ideas as to what could be causing this?

    Thanks in advance for any advise or ideas,

    Don


  2. #2
    Tiny's Avatar
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    Nothing regulates it. It is free flowing in a loop, it returns back to the oil tank....

  3. #3
    So this is oil for the rotary valve. What keeps this oils from getting into the crankcase or cylinders? Is there a seal or something that could be bad?

  4. #4
    wkuadam07's Avatar
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    Yes, your crank seals are bad. There are seals on the crank shaft that keep the oil in that oil bath from getting into the cylinders... yours have shit the bed. Maybe you got lucky and the rotary shaft seal is the only thing bad, but you still have to split the bottom end cases to replace the rotary shaft. Begin testing by pressurizing the oil bath, if it doesn't hold 10 psi for a hour it's going to leak oil into your motor all the time.

  5. #5
    Thanks so much. That is the info I was looking for. I will pressure test it and see. You stated that the crank seals are bad then say that maybe only the seal on the rotary shaft is bad. Are there inner seals on the crankshaft? I don't see any on the drawings for this engine. As you can see I am still a bit confused. It is tough to see exactly where the oil for the rotary valve goes from the drawings. I could under stand what you are saying if the oil goes to the middle of the crankshaft by the rotary gear and is isolated from the rest of the crank housing by two oil seals on either side of the rotary gear that is on the crankshaft. If that was the case then the crank would have to come apart to replace those seals. I see the seal on the rotary shaft and the crankshaft seals on the ends of the crankshaft. Sorry for all the question.

  6. #6
    wkuadam07's Avatar
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    You have it pictured, the crank has to come apart to replace the seals on it there are inner seals that keep the oil bath from getting into the front and back cavities of the case. That is usually what has failed when a rotax starts puking oil. If it doesn't hold pressure take off the carbs and the rotary valve cover, if the rotary shaft seal is bad you will see it leaking and bubbling oil there right there from under the gear. If you are very very careful you can pull the rotary shaft and replace it without splitting the cases, but it's not recommended in the manual... seadoomanuals.net is a mans best friend when in a predicament like you are.
    BTW, if it needs crank seals, it needs bearings... basically a whole crank, then you need a fresh top end to go with that new crank... prepare to save yourself some headache and just drop a reman motor in that unit if the crank seals are where the leak is.

  7. #7
    Great info wkuadam07 and good advise on getting a reman'ed motor if the crank seals are bad. We are in the northeast so this is looking like a winter project. Pull the motor now and drop in a rebuilt one in the spring. I would think if the rotary valve shaft seal was leaking then the oil would be getting sucked into the cylinders and fouling the spark plugs. Thanks again for helping me understand this problem.

  8. #8
    This is how I run a jetski shop in the desert nmpeter's Avatar
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    old wives tale before you change out the engine....

    loop the crankcase oil line and put a few oz of auto tranny seal softener into the line and let it run for a bit, then sit for a bit.

    never heard back from the folks I've given this info too..but it's worth a shot if the seals are leaking into the rest of the engine.

  9. #9
    wkuadam07's Avatar
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    Quote Originally Posted by nmpeter View Post
    old wives tale before you change out the engine....

    loop the crankcase oil line and put a few oz of auto tranny seal softener into the line and let it run for a bit, then sit for a bit.

    never heard back from the folks I've given this info too..but it's worth a shot if the seals are leaking into the rest of the engine.
    I've heard of ppl trying this, one did in another thread in this forum... he ended up needing a motor anyway...
    That trick works if you have a big cloud of smoke at startup and then it's fine, he said this one is spitting raw oil out the exhaust... i'd say he had a seal stick to the crank and get physically torn... tranny leak goo isn't gonna fix that one... but it's worth a try if he doesn't mind taking time to try it, and taking a chance on getting towed in when it fails on the lake one day... lol

  10. #10
    Even if it works initially I would think it would be just a temporary fix.

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