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  1. #1
    Boost Almighty's Avatar
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    heavy mods but Low Speed. HELP

    I have a 08 FX SHO. Making 16.5 psi at 8400 rpms. It has Riva top loader intake grate, rd plate, and jd sponsons. I had it out today and the temps outside where in the 60s air temps. It would only run 76mph. AFR was around 12.5
    It has a stock prop that has been repitched to 13/20.
    This ski should go over 80 with the mods. Any ideas?


  2. #2
    h2jim's Avatar
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    What is your rev limit and are you on it?

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    h2jim's Avatar
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    Never mind. I see you have an R4. What fuel are you using?

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    Your info posted is this correct" R4 Reflash, Riva Intercooler, E1 Wheel, Riva Intake, Riva Intake Grate, Riva Exhaust, TDR Waterbox, R&D Ride Plate, HKS BOV, and Repitched Stock Prop. 13/20"
    If this is correct you are way off on your prop you should be about 14/24 on a scat prop . sounds like you are banging the rvelimiter so hard it's causing the engine to shut off several cylinders spark. Just my opinion! Tommy Jordan

  5. #5
    Boost Almighty's Avatar
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    93.
    I had a R2 before and thought that might have been the problem. I upgraded to r4 and it didn't really see much gain. Maybe 1mph.
    I have been messing with this thing for 3 months.

  6. #6

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    Second thought, DID YOU FORGET TO PULL THE ANCHOR IN BEFOR YOU TESTED! Just kidding, Tommy Jordan

  7. #7
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    It doesn't sound like it's hitting the Rev limiter. Plus the pull off the engine is smooth.

    One thing I noticed when I had the prop out is that when I took it out and put it back in the prop went in very easy. My fzr almost felt like the wear ring was scubbing the prop. On this ski it seems like the wear ring is a loose fit on the prop. It does not cavitate at all though.

  8. #8
    Boost Almighty's Avatar
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  9. #9

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    Quote Originally Posted by Boost Almighty View Post
    It doesn't sound like it's hitting the Rev limiter. Plus the pull off the engine is smooth.

    One thing I noticed when I had the prop out is that when I took it out and put it back in the prop went in very easy. My fzr almost felt like the wear ring was scubbing the prop. On this ski it seems like the wear ring is a loose fit on the prop. It does not cavitate at all though.
    I have ridden a ski hitting the limiter and it's hard to detect the ramdom spark shutting off. If you had excessive prop wear ring clearance you would see cavation real bad on take off. Your prop pitch is way off with 16.5 psi off boost IMO

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  11. #10
    Boost Almighty's Avatar
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    Tommy I have a Solas Concord 14/24 laying around that is brand new. Should I try it out?

    How bout the Riva Intake Grate? I have read good and bad things about those. Could that be hurting my mph?

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