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  1. #1
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    2001 Ranger520DVX w/ 225 Optimax. How can I increase speed?

    Hi Guys, I'd appreciate your thoughts on what else I can try to increase the speed of my boat. I have a 2001 Ranger 520 DVX with a 2001, 225 hp Opti. I'm running a 25 Tempest Plus prop (I have two of them), which I recently had worked on by Holeshot Propeller. Brian added a bit more of a cup to them. I was only getting a gps max speed of 64 mph at 5,540 rpm. I had a 6" Bob's manual jackplate installed last year and gained 1 mph to max at 65 mph at 5,200 rpm. I have it adjusted just deep enough to prevent cavitation on turns. I have often reviewed posts from guys with the same boat and motor getting 70+ mph with approx. the same weight on board. What am I missing here that would make up that difference in speed? I'm wondering if perhaps a higher pitch prop would work. I'm sure many of you have struggled with this same question, and I thank you for your responses.
    Peter C. Takvorian
    2001 Ranger 520DVX/225 Opti.

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    #2
    Quote Originally Posted by boatgypsy View Post
    Hi Guys, I'd appreciate your thoughts on what else I can try to increase the speed of my boat. I have a 2001 Ranger 520 DVX with a 2001, 225 hp Opti. I'm running a 25 Tempest Plus prop (I have two of them), which I recently had worked on by Holeshot Propeller. Brian added a bit more of a cup to them. I was only getting a gps max speed of 64 mph at 5,540 rpm. I had a 6" Bob's manual jackplate installed last year and gained 1 mph to max at 65 mph at 5,200 rpm. I have it adjusted just deep enough to prevent cavitation on turns. I have often reviewed posts from guys with the same boat and motor getting 70+ mph with approx. the same weight on board. What am I missing here that would make up that difference in speed? I'm wondering if perhaps a higher pitch prop would work. I'm sure many of you have struggled with this same question, and I thank you for your responses.
    Boatgipsy,
    do you know what you set up is pad 2 center shaft? you should really find out, since your RPM were at minimum for your motor, yet by adding cup to your pitch will only drop them. When was your motor professionally tuned and fuel system including injectors cleaned? If the JP would b set at proper height , and motor running full power, you should have no problem spinning that wheel at 5700-5850 RPM, which is what mine is turning hitting the limit now and then. Mine is 2003 225HP EFI lightly worked on a 2002 Cobra 201 DC 10" JP set at 3" 70-74.3 depending on load and temps.

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    #3
    Thanks "Dig". I will check the pad to center shaft measurement. I do have the engine professionally serviced each year, but I'm not sure if the injectors and fuel system were "cleaned", other than the fuel filter of course. The plugs were recently replaced however. I will also experiment more with jp height. The rpm's you are getting are exactly what I am looking for, so I welcome your advice. Thanks again.
    Peter C. Takvorian
    2001 Ranger 520DVX/225 Opti.

  5. Member crank68's Avatar
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    #4
    If the rails and injectors have not been serviced, they need to be.

    Bullet 20 XRD/250 MercSport XS

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    #5
    Get the rails and injectors cleaned and calibrated not just cleaned. You should be able to run 68-69 if everything is right.

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    #6
    After you get the fuel system work completed adjust the motor so that the lower unit is 3 1/4" below pad. A 25" Tempest plus should work best on that hull. If the prop work is good you should see 68-70.

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    #7
    Great advice guys, I really appreciate the responses and now I know exactly what I will pursue next. I'm far more confident that my efforts will be effective! I'm so glad I posted my issue on this site.
    Peter C. Takvorian
    2001 Ranger 520DVX/225 Opti.

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    #8
    How long have you owned the boat? Seems to me that your rpms are very low. Be prepared for sticker shock on fuel rail cleaning...

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    #9
    BTW, what fuel do you use? I hope you are NOT USING the Ethanol poisoned crap low grade. I have found 91 with NO ETHANOL + ring free and Starbright fuel enzyme additives will keep system in great shape. However, I get my injectors cleaned and calibrated every few years, and check my cylinders compression to make sure of no rings or bore issues.

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    #10
    High octane gas in a opti max only carbons it up and the motor is designed to run on 87 octane 10% ethanol gasoline. That regular opti max will never run like that 2003 225 efi.
    Last edited by mdtritn21; 01-12-2017 at 04:32 PM.

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    #11
    Quote Originally Posted by mdtritn21 View Post
    High octane gas in a opti max only carbons it up and the motor is designed to run on 87 octane 10% ethanol gasoline. That regular opti max will never run like that 2003 225 efi.
    Well, my Merc Premier certified tech runs my same combination in his 2012 250 Pro SX hanging on a Puma FTD with NO issues. BTW, unless you are running thru a tank a week, I would not use any ethanol poison fuel, especially since the halfwits at EPA are pushing for more ethanol do to farming lobbying.

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    #12
    I just run 87 octane poison in my efi like yours and it runs pretty good.

  14. Member crank68's Avatar
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    #13
    The mota is designed to run on 87...

    Bullet 20 XRD/250 MercSport XS

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    #14
    Quote Originally Posted by crank68 View Post
    The mota is designed to run on 87...
    Even sirloin steak is better than hamburg. For a couple of dollars more, I will let mine have sirloin.

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    #15
    Quote Originally Posted by digthemup View Post
    Even sirloin steak is better than hamburg. For a couple of dollars more, I will let mine have sirloin.
    You must not know how fuel and grades work?

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    #16
    Quote Originally Posted by digthemup View Post
    Even sirloin steak is better than hamburg. For a couple of dollars more, I will let mine have sirloin.
    Lol, might live better if you feed it only lean meat.

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    #17
    Your motor does not have the compression require to take advantage of high grade fuel, you will get a slow incomplete burn and performance will suffer.

    Run some 87 through it and you might pick up some rpm.

    Also those boats like a lot of set-back , we've picked up mph going to 10-12" back on a few rigs.

    Tempest is a good prop for it.

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    #18
    Quote Originally Posted by Fishysam View Post
    You must not know how fuel and grades work?
    I know you are referring to the autoignition point of 87 vs 91 vs 93. That point is not that great of a concern between 87 vs 91 that it is 87 vs 93 or higher(racing fuels 95-110).
    However, 87 may burn at a lower point, but it will knock lower as well, which can give you bigger issues to your motor than the slightly less burn of 91, which allows your to mess with timing if you prefer to squeeze a little more HP.
    Remember, unlike a 4 stroke, a 2 stroke fires 2x as much running a hotter piston top temp. I know I may not be the sharpest tool in this shad, but I may know a thing or 2.
    Just having a polite exchange of conversation, NOT a dick measuring contest.

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    #19
    Quote Originally Posted by 90 5.0 View Post
    Your motor does not have the compression require to take advantage of high grade fuel, you will get a slow incomplete burn and performance will suffer.

    Run some 87 through it and you might pick up some rpm.

    Also those boats like a lot of set-back , we've picked up mph going to 10-12" back on a few rigs.

    Tempest is a good prop for it.
    90 5.0
    You are right that more set back in a specific hall and set up will give you a few more MPH, but that can only be determined by trial and error until you find the best combination of hall+motor+setback+prop= lots of time and money. Now, let say your rig tops off at 85-90mph, dang that is not even the top of 3 gear on my Roush Stage3, with a few more to go.
    BTW, we have 88 GT T tops, 89 Saleen SCCA Showroom, 90 7-up convert all 5.0's

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    #20
    87 burns faster/ complete. 91 isn't all being burned, the stroke isn't enough... Pollution/carbonizing

    ping, knock, detonation doesn't happen in a two stroke, unless your gas is old or your hopped up.

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