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  1. #1

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    2018 RXTX300 Cutting out under boost

    2018 RXTX300 with just shy of 200 hours on it running flawlessly with a JP racing tune on it. June 12th I took it out in the morning and it ran perfect on the way out. On the way back, I had to run through a long no-wake zone. When I went to take off, the motor did it's normal condensation "hiccup" that happens after a no wake zone when it's 90 degrees and 100% humidity. This time though, it never recovered like normal. Since then, any time I hit boost, the ski falls flat on it's face. I pressure tested the intercooler, but did not find a leak. Prior to that, I did pour the water out of it into a cup when I removed it to do a test and when I tasted it, it was salty. (ran in saltwater that day) Threw a set of spare plugs, ordered new ones, in it and took it out the next weekend. Same thing, but worse. New plugs gapped at 28 thousands, exact same symptoms. Pulled them out and the tips are white. Never seen that before on this ski, even with new plugs. So with that said, I have 2 suspicions:
    -fuel pump going out
    -intercooler has a leak under vacuum that does not show under pressure testing.

    After reading the manual, is there a way to test fuel pressure without the seadoo tool? I was thinking of adding in a "T" on the factory hose and throwing a fuel pressure gauge on it. Any reason that wouldn't work?

  2. #2

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    Problem solved...leaking intercooler. New fizzle residing in the ski now.

  3. #3

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    Quote Originally Posted by Wildjon3006 View Post
    Problem solved...leaking intercooler. New fizzle residing in the ski now.

    Spoke too soon. Still having issues, just nowhere near as severe. Ski pulls hard to 8k...and then it chokes and takes several seconds to recover. Prop that I have in it turns 8400 normally. Not sure what's going on, but going to have the injectors and fuel pressure tested tomorrow. Even though these are 2 ride old plugs, going to go ahead and replace with new as they were in the ski with the leaky intercooler.

  4. #4

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    Quote Originally Posted by Wildjon3006 View Post
    Spoke too soon. Still having issues, just nowhere near as severe. Ski pulls hard to 8k...and then it chokes and takes several seconds to recover. Prop that I have in it turns 8400 normally. Not sure what's going on, but going to have the injectors and fuel pressure tested tomorrow. Even though these are 2 ride old plugs, going to go ahead and replace with new as they were in the ski with the leaky intercooler.

    Haven't changed the plugs yet, but did try a new MAP sensor. Didn't fix the cut out. Doing an oil change this week, so I'll change the plugs and check SC slip.

  5. #5

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    Another guy here was losing power under boost. Hose on the supercharger. I am assuming you checked all your hoses already?

    Post

  6. #6

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    Quote Originally Posted by jeff24680 View Post
    Another guy here was losing power under boost. Hose on the supercharger. I am assuming you checked all your hoses already?

    Post
    No boost leaks. Double and triple checked. Issue started with leaky intercooler.

  7. #7
    Mod less, ride more! troyheb's Avatar
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    SC is slipping. 200 hrs is supposed to be their life span.

  8. #8
    Team Bilford's Avatar
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    Quote Originally Posted by troyheb View Post
    SC is slipping. 200 hrs is supposed to be their life span.
    The service manual states to inspect the SC at 200 hours. It does not say that is the service life.
    The manual does not give any detailed instructions on what this "inspection" involves. It doesn't even say to check the slip.
    There are many many 300s with 400+ hours and no SC work at all, but this machine is not stock either.....


  9. #9

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    MAP sensor and plug. That's what the issue was.

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  11. #10

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    Quote Originally Posted by Wildjon3006 View Post
    MAP sensor and plug. That's what the issue was.
    Thank you for coming back and letting us know!!

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