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  1. #1

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    Long time no update....

    So last summer I had a problem getting my RXT 300 past 81'ish. So starting over from scratch and installing the Riva Stage III plus kit, I managed to maintain 87 mph.

    I was thrilled to death until it let loose and detonated the engine. I was in a dilemma, I had two years of warranty left but had I turn my ski to a dealer to have it covered under warranty, it would have been denied. The moment BRP saw over 8K tach readings, I was screwed.

    I drove from NC to FL and dropped it off at my favorite performance dealership. It turns out that the problem came from the rocker arms that exploded... turns out that weak rocker arms were breaking on bone stock 300's.

    I was able to get a new engine but haven't put it together yet because there are no replacements available for rocker arms and lifters other than stock (well, one company but apparently they're not ideal)

    Riva is in the process of making their own rocker arms and billet lifters. Once that's designed and implemented, my engine can be put together.

    At this point, I'm not looking for anything faster, I'd rather have it more bulletproof than faster. I've been waiting for 6 months so far, another month or so won't hurt.

    Just thought I'd give an update.

    Mark


  2. #2
    Faster? I'm a nut but 87 is plenty !! WOW!!

  3. #3
    SplishSplash's Avatar
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    Rocker arms breaking? Has anyone else heard of that on the 300's. What rpm's were you turning? Are you sure the rocker's breaking were the cause or a result?

    Cool dealer to cover it.

  4. #4
    www.eastcoastpwc.net Scott's Avatar
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    Yes. I've heard of a handful or so breaking rockers.

    I sent Riva my bone stock 2018 spare cylinder head back on August 1st 2019 to help expedite their billet rocker project. Last I heard it shouldn't much longer...
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  5. #5
    moparguy's Avatar
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    Quote Originally Posted by SplishSplash View Post
    Rocker arms breaking? Has anyone else heard of that on the 300's. What rpm's were you turning? Are you sure the rocker's breaking were the cause or a result?

    Cool dealer to cover it.
    Wicked broke em at 9k on his turbo px, he got lucky no internal damage. That's the only other instance I've heard of them breaking.

  6. #6
    SplishSplash's Avatar
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    Quote Originally Posted by Scott View Post
    Yes. I've heard of a handful or so breaking rockers.

    I sent Riva my bone stock 2018 spare cylinder head back on August 1st 2019 to help expedite their billet rocker project. Last I heard it shouldn't much longer...
    Wow, that cam looks like impact, not wear damage! Some real pressure was applied there and broke the rocker! Valve Float?
    No billet rocker will fix that.

  7. #7
    www.eastcoastpwc.net Scott's Avatar
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    Quote Originally Posted by SplishSplash View Post
    Wow, that cam looks like impact, not wear damage! Some real pressure was applied there and broke the rocker! Valve Float?
    No billet rocker will fix that.
    Not my ski, but photos that were passed along to me. Ski did drop a valve and rest was history. I believe supertech springs, riva cam and stock rockers/valves was the setup.

  8. #8
    Bob 1tommygunner1927's Avatar
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    Quote Originally Posted by Scott View Post
    Not my ski, but photos that were passed along to me. Ski did drop a valve and rest was history. I believe supertech springs, riva cam and stock rockers/valves was the setup.

    I'm thinking valve springs probably should be changed every 3-4 seasons! Now, on these new rocker arms, are they billet aluminum or other?

  9. #9
    www.eastcoastpwc.net Scott's Avatar
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    Quote Originally Posted by 1tommygunner1927 View Post
    I'm thinking valve springs probably should be changed every 3-4 seasons! Now, on these new rocker arms, are they billet aluminum or other?
    Honestly, not sure. No information has yet to be released. But will require manual adjustment for valve lash etc.

    willing to bet will be VERY SIMILAR to this

    https://aquasportperformance.com/sea...ocker-arm-set/
    Last edited by Scott; 01-16-2020 at 10:33 AM.

  10. #10
    marcroberts's Avatar
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    Yep it happens heavy stock valves good springs and 9000 plus rpm. I change rockers every season now.Click image for larger version. 

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