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  1. #1

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    Cool can the stock tach be trusted?

    I just went out last weekend on my o7 ultra 250x and the top speed registered was 70mph at 7340rpm. I know the speedometers are inaccurate, but are the tachometers( digital and analog)? Oh yeah,the ski has;R&D offshore rideplate,TBM intake grate(don't worry I don't run the the adjustable foil),pump shoe seal kit, R&D 2 degree pump wedge,block off plates, billet supercharger hub,R&D tensioner wheel,R&D powershot,Riva air intake,Riva blowoff bypasskit(I think that is what it's called), riva exhaust bypass,riva pro waterbox,R&D intercooler kit and a few secret mods to my intercooler and exhaust. oops also the degree timing mod. The air was about 65,water temp almost 70 in Edenton ,N.C. Big thanks to MR. SKIP HOLMES. Your tips are priceless chief. Stock skis are for wimps.hehe


  2. #2
    GODOSIDIS's Avatar
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  3. #3
    benjahw benjahw's Avatar
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    The Tach is definately more accurate than the speedometer. And at 7300 RPM, you are WAY low. something isnt right. you should be running around 8000 rpm i think with the timing mod, intake and exhaust..


    I hope the Registered speed and rpm was not your MAX RPM. do you remember what your rpm's were reading when you had it Pegged?

  4. #4

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    Cool

    that was the max recorded by the memory,ya know when you flip through the different modes. I know my speedo is worthless. At max throttle in smooth water,she's only readin' 54 to 55 . I need gps

  5. #5
    DWRAT's Avatar
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    The max recall cannot be trusted at all but the tach itself is dead on.
    I had the same problem with the max recall, it was 70mph and about 7000 or so.

  6. #6

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    honestly, i've been trying to remember max rpm when riding and it hovers around 7500 7600 rpm. still way low. probably dumb question but could a leaky blowoff valve be the culprit.less boost equals less horsepower equals less rpm right.

  7. #7
    DWRAT's Avatar
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    If your hitting 70 on your speedo your doing just fine.

  8. #8
    nicjak's Avatar
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    Quote Originally Posted by eazygoin View Post
    honestly, i've been trying to remember max rpm when riding and it hovers around 7500 7600 rpm. still way low. probably dumb question but could a leaky blowoff valve be the culprit.less boost equals less horsepower equals less rpm right.
    maybe next time take note as you more than likely dont have a problem you need to watch the tacho at full noise and remember the reading the max rpm saved is only an indication when the speedo maxxis out at 70

  9. #9
    hudsta's Avatar
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    Quote Originally Posted by eazygoin View Post
    honestly, i've been trying to remember max rpm when riding and it hovers around 7500 7600 rpm. still way low. probably dumb question but could a leaky blowoff valve be the culprit.less boost equals less horsepower equals less rpm right.
    If you are only hitting 7600 rpm when you check ....
    i would take the powershot tuner off and see how it goes then ,there is not much use for it unless running a pulley and injectors, Alot of people have had problems with them .

  10. #10
    Formerly Ultra250 TN Aquaholic6801's Avatar
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    With the mods you listed you should be over 8000 rpms............Minus the Power Shot

    Quote Originally Posted by hudsta View Post
    If you are only hitting 7600 rpm when you check ....
    i would take the powershot tuner off and see how it goes then ,there is not much use for it unless running a pulley and injectors, Alot of people have had problems with them .

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