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  1. #1
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    Nose cone and prop

    Hey guys

    i just finished my Nose cone and took the boat for a test run.
    the reason I mounted the cone was that I needed lwp since I couldn’t raise the engine high enough without loosing pressure, And I needed more lift since the boat was running to flat and with a lot of chinewalking. so my guess was that the engine needed to run higher and with a bigger/other prop.
    my goal was to reach 85+ mph.

    the boat: Fletcher 199, 225 optimax, 6” setback, hydraulic jack plate.

    before installing the nose cone:
    propshaft 1.5” below the pad.
    27p tempest plus (blueprinted & labbed).
    WOT 77-80mph/5600-5650rpm.

    after installing the nose cone:
    propshaft in Level with the pad (jack plate is at maximum height)
    27p tempest plus (blueprinted & labbed).
    WOT 68mph/5200rpm.

    what the hell happened?

    i then tried a stock 28p promax (4 blade) and this gave a bad hole shot (guess because it hasn’t got pvs holes as the tempest), but I got a rock solid boat without any chinewalking at all.
    WOT 73mph/5450rpm.

    The million dollar question is now:
    1). can the promax be modified to a 29-30p and at the same time be labbed to getting around 5600 rpm.
    2). should I dismount the jack plate and raise it so I will be able to getting the propshaft 1-2” above the pad.

    Please give me your thoughts guys ��

    thomas
    Last edited by Ttl; 05-10-2020 at 12:50 PM.

  2. #2
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    I'd try some more props. Cleaver, chopper, lightning etc
    Hydrostream dreamin

  3. #3
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    Does it have less bow lift with the prop running higher?

  4. #4
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    Yes I think it does

  5. #5
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    Any prop shops near you? Get some cup added it should help with lift. Trophy is another I forgot to mention, I havent tried one yet but plenty of fans for the holding power of that prop. Mazco is another that has good lift. I have a Mazco as well and its good but the chopper I have which has been massaged more times than I could ever tell holds really really well. It is a pain to get out of the hole with a stock through hub exh but it grips and lifts big time under power
    Hydrostream dreamin

  6. #6
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    Try props with more lift or try lowering the engine. I think you get more lift lower

  7. #7
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    Ya the higher u run the less lift u get , I been kinda fighting same thing , I just put a trophy on and it's better but the trophy needs little work to be what I want , I want a bravo xs to try. Also a stock big ear chopper has great lift ,

  8. #8
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    Sounds like your boat needs bow lift which mean positive engine trim. By adding a LWP you made your gearcase longer. With positive trim, a longer gearcase creates more drag which may be slowing you down. Yes, raising an engine will reduce bow lift but it will also get more of the gearcase out of the water reducing drag. A power jackplate will save you a lot of setup time. Also, increased setback may help to get you bow lift back at higher engine heights.

    I'm in a similar situation...Sportmaster lower, heavy setup, and mid to upper 70's for speed. I run about 1"-2" above the pad for speed. At the higher engine heights with positive trim, larger diameter props with lots of cup seem to work the best -- Scorpion 3-blade or mod'd Bravo. I also like the TXP OT4. The Promax was great for speed but terrible, surging hole shot.

  9. #9
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    Quote Originally Posted by Merc 2.5 View Post
    Ya the higher u run the less lift u get , I been kinda fighting same thing , I just put a trophy on and it's better but the trophy needs little work to be what I want , I want a bravo xs to try. Also a stock big ear chopper has great lift ,
    This is what I have found too. Wicked grip and bow lift with the big ear chopper I dont need any trim
    Hydrostream dreamin

  10. #10
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    Quote Originally Posted by lance View Post
    Sounds like your boat needs bow lift which mean positive engine trim. By adding a LWP you made your gearcase longer. With positive trim, a longer gearcase creates more drag which may be slowing you down. Yes, raising an engine will reduce bow lift but it will also get more of the gearcase out of the water reducing drag. A power jackplate will save you a lot of setup time. Also, increased setback may help to get you bow lift back at higher engine heights.

    I'm in a similar situation...Sportmaster lower, heavy setup, and mid to upper 70's for speed. I run about 1"-2" above the pad for speed. At the higher engine heights with positive trim, larger diameter props with lots of cup seem to work the best -- Scorpion 3-blade or mod'd Bravo. I also like the TXP OT4. The Promax was great for speed but terrible, surging hole shot.
    i do have a hydraulic jackplate. I’ve just modified my nose cone and hoping it will reduce drag.
    i think I will drill some vent holes in my promax to gain better hole shot.

    a chopper is crap on my boat and don’t work for me
    Attached Thumbnails Attached Thumbnails D0D076B5-CDAC-4931-BCAB-B5E98CBA2084.png   21ECCF95-B580-4CCA-8CC9-24BF24F6E18F.jpg  

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  12. #11
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    How is the motor only 11/2 inch up using a jackplate ? the jack plate should be able to lift that motor atleast 5 inches higher than you previously had it.
    what are you doing exactly to have it this low when motor is raised fully up ? are you mounting the motor on its lowest holes and have the jack plate itself mounted too low ? most jack plates will automatically have atleast 1 inch lift without even moving the plate up, then you have the rest of the lift itself, so I cannot see how your only up 1 1/2 inches. or is this a case of you dont want to run it higher and get the bullet riding on top of the water ?
    where is the cavitation plate running now you have the jack plate on at full throttle / you need that to be above the water by about 2 inches. the lwp will do the job of getting plenty of water pressure even if you go up another3 inches... you realy need to see what is happening at the cav plate when running on the plane.. to me it sounds like your too deep, and with the cone you have more case in the water causing more drag... and if plate is lowthat will also be getting drag

    just how im seeing this..

  13. #12
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    You raised the motor 1.5 inches and LOST 400 RPM??? This just doesn't seem possible
    Living in the Freedom provided by Bud Conner and his fellow warriors.
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  15. #13
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    Weak coil

  16. #14
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    Weak something
    Living in the Freedom provided by Bud Conner and his fellow warriors.
    R.I.P. my Heathen Brother






  17. #15
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    You didn't do anything other then the nose cone and raise the motor... weren't under the cowl at all hit a wire etc?
    LETS GO BRANDON.... LETS GO BRANDON

    Sometimes I talk to myself...then we both just laugh and laugh

    '84 Checkmate Convincor

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