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    GP1800 and Riva Stage 1 intake grate

    Hey all-
    I am looking for advice.. 2018 GP1800, stage 1 tune, ribbon delete, ran 79 on GPS. I bought a Riva gen 1 intake grate, filled the cavities with flex steel, trimmed the 3 inside tabs off the intake grate seal and used marine grade silicon all around the grate to seal her back up. I lowered my stock ride plate to reinstall the intake grate and buckled her back up. Ski is down to 71.9mph on GPS. I threw the stock grate back on it and same thing. Any suggestions? I am going to check for a boost leak but she bounces off the rev limiter when she cavitates so I dont think I have a boost issue. Might try changing the plugs as I have 54 hours on her.. Everything else is stock besides the above mentioned.. I want my upper 70's back..


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    BLASTER 1's Avatar
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    Quote Originally Posted by Paulpa View Post
    Hey all-
    I am looking for advice.. 2018 GP1800, stage 1 tune, ribbon delete, ran 79 on GPS. I bought a Riva gen 1 intake grate, filled the cavities with flex steel, trimmed the 3 inside tabs off the intake grate seal and used marine grade silicon all around the grate to seal her back up. I lowered my stock ride plate to reinstall the intake grate and buckled her back up. Ski is down to 71.9mph on GPS. I threw the stock grate back on it and same thing. Any suggestions? I am going to check for a boost leak but she bounces off the rev limiter when she cavitates so I dont think I have a boost issue. Might try changing the plugs as I have 54 hours on her.. Everything else is stock besides the above mentioned.. I want my upper 70's back..
    Yes, change the plugs then report the results

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    BLASTER 1's Avatar
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    Quote Originally Posted by Paulpa View Post
    Hey all-
    I am looking for advice.. 2018 GP1800, stage 1 tune, ribbon delete, ran 79 on GPS. I bought a Riva gen 1 intake grate, filled the cavities with flex steel, trimmed the 3 inside tabs off the intake grate seal and used marine grade silicon all around the grate to seal her back up. I lowered my stock ride plate to reinstall the intake grate and buckled her back up. Ski is down to 71.9mph on GPS. I threw the stock grate back on it and same thing. Any suggestions? I am going to check for a boost leak but she bounces off the rev limiter when she cavitates so I dont think I have a boost issue. Might try changing the plugs as I have 54 hours on her.. Everything else is stock besides the above mentioned.. I want my upper 70's back..
    Yes, change the plugs then report the results.
    If there was no change check for boost leak and your clutch

  4. #4
    I changed the plugs out and same result. I am thinking of putting the stock intake grate back on it and buying a new stock rubber seal to see what that does for me. Let me know if you have any other suggestions..

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    BLASTER 1's Avatar
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    Quote Originally Posted by Paulpa View Post
    I changed the plugs out and same result. I am thinking of putting the stock intake grate back on it and buying a new stock rubber seal to see what that does for me. Let me know if you have any other suggestions..
    Did you check your clutch, they can slip and make your ski feel like it’s cutting out and definitely not get to top speed

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    BLASTER 1's Avatar
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    You also want to check for a boost leak. Check hoses and clamps from charger to cooler to TB. Check exhaust hoses and clamps too

  7. #7
    Supercharger is fine, spins only 1 way.. No boost leaks either.. I will check the exhaust hoses and clamps.. This all happened when I installed the Riva gen 1 intake grate, I believe has something to do with that. I appreciate your help!!

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    Click avatar for tech links/info K447's Avatar
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    Quote Originally Posted by Paulpa View Post
    ... 2018 GP1800, stage 1 tune, ribbon delete, ran 79 on GPS.

    ... Riva gen 1 intake grate, filled the cavities with flex steel, trimmed the 3 inside tabs off the intake grate seal and used marine grade silicon all around the grate to seal her back up.

    I lowered my stock ride plate to reinstall the intake grate and buckled her back up.

    Ski is down to 71.9mph on GPS. I threw the stock grate back on it and same thing. ...
    There may be something going on with the flat rubber seal between ride plate and intake grate. Cutting the rubber fingers off may allow the rubber to flex up and/or down. There is a lot of water force in that area.

    Did you seal the back rim of the intake grate to the transom plate?

    Is the front lip of the ride plate sealed to the hull and transom plate across the entire width?

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    Quote Originally Posted by Paulpa View Post
    Supercharger is fine, spins only 1 way.. No boost leaks either.. I will check the exhaust hoses and clamps.. This all happened when I installed the Riva gen 1 intake grate, I believe has something to do with that. I appreciate your help!!
    Ok, I don’t see how installing your Riva grate would cost you 7mph
    Im still thinking it’s your clutch slipping. It usually spins both ways when it’s gone but will still lock up with your fingers when it’s slipping under power. That’s exactly what it was doing to me

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    Hey Paulpa, what were your max rpms doing 79 then at 72

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