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Thread: Slow GPR

  1. #1

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    Slow GPR

    Hello I recently picked up a 2003 GP1300R, It runs strong and pulls hard however i've only managed to get 60.8mph out of it on GPS and around 7100RPM. hard to tell on stock gauge.

    It has a Riva pump plug kit,
    Solas 13/19
    and an R&D 800 grate, and a Riva 1200.

    The water was flat to slight ripples, air temp was 30C, elevation 850ft above sea level, rider weight approx 195lbs, speed was taken with a gps.

    the 800 was on when I got 60.8, it seams to be a bit slow to what the stock speed should be, and i'd like to find where im losing the speed before I get any more mods. The plate and tab are shimmed from the previous owner, looking under neath the hull nothing appears to be hanging low causing drag, and the wear ring looked to be okay wasn't much clearance between the prop.

    Any ideas on where im losing speed?

    Thanks.


  2. #2
    RHeller1's Avatar
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    put the tabs and plate back to normal and start over with the testing and shimming. Is the pump shoe hanging down past the hull?

  3. #3

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    Quote Originally Posted by RHeller1 View Post
    put the tabs and plate back to normal and start over with the testing and shimming. Is the pump shoe hanging down past the hull?
    Pump Shoe is level with the hull.

  4. #4
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    Quote Originally Posted by Harris View Post
    Hello I recently picked up a 2003 GP1300R, It runs strong and pulls hard however i've only managed to get 60.8mph out of it on GPS and around 7100RPM. hard to tell on stock gauge.

    It has a Riva pump plug kit,
    Solas 13/19
    and an R&D 800 grate, and a Riva 1200.

    The water was flat to slight ripples, air temp was 30C, elevation 850ft above sea level, rider weight approx 195lbs, speed was taken with a gps.

    the 800 was on when I got 60.8, it seams to be a bit slow to what the stock speed should be, and i'd like to find where im losing the speed before I get any more mods. The plate and tab are shimmed from the previous owner, looking under neath the hull nothing appears to be hanging low causing drag, and the wear ring looked to be okay wasn't much clearance between the prop.

    Any ideas on where im losing speed?

    Thanks.

    how many hours on the top end?

    whats the compression like?

    so many things it could be but i would start by looking at those two first.

    2 strokes start to get tired after 120+ hours.

    also how are you measuring your speed and rpm? with gps and after market tach?

  5. #5
    CHICKA WAH WAH bren's Avatar
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    Quote Originally Posted by izz0 View Post
    how many hours on the top end?

    whats the compression like?

    so many things it could be but i would start by looking at those two first.

    2 strokes start to get tired after 120+ hours.

    also how are you measuring your speed and rpm? with gps and after market tach?

    so true

    maybe dont worry bout the aftermarket tach though, unless you got some time machine to slow schite down to read its slow display pulse.

    reckon the top end will be a bit tired like Izzo said

  6. #6

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    Theres around 120 hours on the top end, I planned on rebuilding it over the winter. I can't remember what the compression was, but I should be getting my compression gauge soon.

    I'm using GPS to record speed a Garmin Etrex, an after market tach is amongst the pile of parts to get over the winter.

  7. #7
    Nothin' runs like a Deere IowanGPR's Avatar
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    Quote Originally Posted by Harris View Post
    Pump Shoe is level with the hull.



    you want the pump shoe about a nickel thickness from the hull

    if you put a straight edge on the hull you should be able to push a nickel through, or almost. mine doesn't quite fit but all the way front to back is the same.

  8. #8

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    Quote Originally Posted by IowanGPR View Post



    you want the pump shoe about a nickel thickness from the hull

    if you put a straight edge on the hull you should be able to push a nickel through, or almost. mine doesn't quite fit but all the way front to back is the same.
    THanks

    Ok, I'll check it when I get up to it. No room to store it here.

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