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  1. #1

    Low top speed and not reaching max rpm?

    Ok here it is. 02 f12 na. Stripped out old engine. Replaced with a brand new engine from an 06 w 0 hours. Also used computer all wiring harnesses and gauge from the same 06 na ski the engine came from. We completed a proper break in road it a few times after break in but didn't have a chance to run it hard due to rain and rough water. Finally got a 60 degree day in Seattle and ran it in a calm river. What I found was that we maxed out at 50 mph and 6930 rpm. This on glass not a ripple at all. Also feel and here a vibration at max speed. Almost sounds and feel like something in the pump but we have done a very thorough inspection and the pump is clear. It pulls hard from idle and jumps out of the water. It's just dogging on top. Any thoughts or suggestions? I thought max rpm on an na is supposed to be in the realm of 7750. Btw I get no codes at all. This thing runs perfect everywhere except on top. Could the low speed be caused by pump? Impeller? Is the 06 na using a different impeller pitch than an 02? Am I off base thinking pump? Any help is appreciated.


  2. #2
    JRINJAX's Avatar
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    There were differences in the engines in the later model NAs so the pump might be different. Make sure your coupler is aligned properly too.

  3. #3
    I put a strobe on the coupler and found no variations in it. It appears to be straight and true with and no vibration. I don't have the fancy shmansey Honda tool but I did measure the gap in the coupler all the way around and it is damn even.

  4. #4
    JRINJAX's Avatar
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    The best way to set a coupler up is with a swinging dial indicator, barring that, use a machinist straight edge to set parallel alignment and then a feeler gauge all around it to correct any angular misalignment. You can get it very close this way with some patience. A friend just bought the Honda tool that lives in MD.

  5. #5

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    Hello,
    Honda changed the pump and raised the HP ratings on the 2005 and newer natural engines, they went from 125 to 137.5 in 2005. they also raised the rpm and changed the pump. mine runs about 7800 at full speed. i know they also changed the pump on the 2005 and newer non turbo
    Change the plugs on it and see if that helps, the honda's are very sensitive to plug condition and you really cannot clean them. The best place to buy them is at discount auto parts stores, about 10.00 per plug vs honda dealers 17.00 each.
    also buy good gas, 91 octane the honda's need good gas or performance will suffer.

    good luck i will be a month or so before we will ride in Indiana as the ice just went away last weekend and it was high of 45 degrees today.

    Mike

  6. #6
    JRINJAX's Avatar
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    We too are "suffering in Florida" with cold weather, it was 91 Saturday two weeks ago and 84 last Saturday. Life here is really tough....

  7. #7
    Dude that's messed up. We have to wear dry suits and 7mm booties and gloves and full face masks. Although on the good side if we are having fun on a river and fall off we don't have to worry about getting eaten by gators. Lol.

    ---------- Post added at 11:46 AM ---------- Previous post was at 11:45 AM ----------

    So if it is a pump issue can I get away with changing the impeller or due I have to swap the whole pump?

  8. #8
    JRINJAX's Avatar
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    We really pay no attention to the gators. We only brought them here to scare off the Tourists.

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