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  1. #1
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    Xpress h51db best setup

    Have an 04 h51db with an 03 Mercury 90hp 2 stroke. Has 6 inch jackplate, 22p powertech prop, prop shaft 5” below pad, 5500 wot. Was running 51 mph gps then added two more batteries and speed dropped to 43. Doesn’t seem to get on the pad anymore. Adding a passenger and full livewell does not affect the speed. Only the batteries hurt the speed. Any advice on best setup/ weight distribution for this rig? Thanks

  2. Arkansas Rally Moderator Arkyarcher's Avatar
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    #2
    Might try raising the motor since more weight in back makes it lower in water.
    Gene Wilson

    2000 Xpress X19 Mercury 200
    Team PoorMansCustomLures

    Two wrongs don't make a right , but three lefts do.

  3. Member
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    #3
    What were your RPM's at 43 mph?
    1998 Xpress H51, 90hp Yamaha, 6" Vance JP, MotorGuide Xi3, Lowrance Electronics, Micro Power Pole...

  4. Member
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    #4
    About 5500. It didn’t drop the rpm much from adding the batteries. Just got slower. It’s like the stern is dragging instead of hopping up on the pad. Still gets on plane quick and rides good, just doesn’t have that on pad feeling that it had before adding the batteries. And it’s a lot slower.

  5. Member
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    #5
    Remove the two batteries, and re-test...see if you can reach 51 mph again with 5500 rpm's.
    I can't see where 120 lbs. extra weight would cause a drop of 8 mph.
    Last edited by bulldog44; 11-29-2018 at 10:02 AM.
    1998 Xpress H51, 90hp Yamaha, 6" Vance JP, MotorGuide Xi3, Lowrance Electronics, Micro Power Pole...

  6. Member
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    #6
    Turns out the tach was way off. Even on the right setting it was 700 rpm off at WOT. Now 47mph with full love well and second person.

  7. Member
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    #7
    So, 6200 rpm's @ 47 mph, two persons, full live well...Is this also with the two extra batteries?
    If so, that's about as good as one could have with a H51 & 90 hp motor.
    1998 Xpress H51, 90hp Yamaha, 6" Vance JP, MotorGuide Xi3, Lowrance Electronics, Micro Power Pole...

  8. Member
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    #8
    When I first got the boat it had one battery and I was running 51 mph with no tach and hit 51 mph (gps). I added a new tach and two more batteries. At 5500 (tach) I was running 43 mph so I suspected the tach was off so I added a digital tach to the spark plug. My analog tach was 700rpm higher than the digital tach. So now I am running a true 5500rpm and my analog shows 6200. Now running 47 mph (gps) with three batteries, full live well and 250lb passenger. 5500 rpm is where I should be for a mercury 90hp.