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  1. #1
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    2000 Bumblebee Setup

    I posted this on the 4 Stroke Mercury board as well, but I thought this would be a good place as well. I have a 2000 Bumblebee 180 PRO VEE that I just put a new 175 pro xs 4s on it with a 23p fury. I have owned this boat since it was new and it had a 175 efi 2 stroke on it until it blew up with a 25 tempest. It used to run mid 60s at 5800 RPM loaded. It is an 18 foot boat and dry hull weight is 1050 pounds. It is at 2 1/2 inches PTP. I have 3 hours on it now and I just put the mercmonitor on it so I could get accurate data. Today I opened it up a few times and my peak speed was 61.3 at 5350 RPMs. I feel that it started chine walking 3 or 4 mph earlier than it used to and it was lifted out of the water earlier as well. I don't think it used to start walking bad until 63mph or so. I also had hydraulic steering put on it and that's taking some getting used to when it starts walking. It was a little rough and windy today so I'm going to try again on a calmer day, but I don't think it's going to get 500 RPM better. Do I need to play with engine height or a different prop?


    *Edited to change PTP to 2 1/2 inches instead of 3 1/2. Im bad at math.
    Last edited by hydroplane; 08-26-2019 at 07:09 PM.

  2. Banned
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    #2
    Wait till the motor is broke in and you can put some longer runs on it then adjust.

  3. Member
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    #3
    Your new motor is 55 lbs heavier but it will turn 6000 rpm's or at least that's what the specs say. You may need go to a 23" tempest since it will run higher prop to pad than a fury will which will allow it to turn more rpm's and reduce the chine walk.

  4. Member
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    #4
    Update: I was having issues getting my prop to pad measurements correct. I couldnt measure the same thing twice. I have figured out what I was doing wrong plus my garage floor is not as level as it looks. Now I can re-create the measurements and they match up with how much I have raised the motor. I actually started at 4 1/8".

    4 1/8" - 61.3@5350 RPM 21 PSI
    3 1/2" - 61.4@5350 RPM 21 PSI (Chine walk got way easier to handle and everything felt good again)
    3 1/4" - 60.3@5230 RPM 21 PSI (Added 8 Gallons of Gas(might explain 1mph drop?), no noticable change in handling)
    3" ???

    Is it strange that I have raised the motor almost an inch and there has been no noticable change in anything? Would this be an indication that I am not getting 100% throttle? I have contacted the dealer today and asked if they even checked it and I didnt get a good answer just that I could bring it down and they would check it. I have it set to 3" now, but havent driven it yet. I think I need to verify that I am getting 100% throttle before I continue. Any thoughts?

  5. Banned
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    #5
    As Pat says take it too far then you will know. If you have came up and no major changes keep coming up till it does then you will know to drop it back down.

    Yes weight will effect performance. When you adjust a setup do it with a "tournament load" full of fuel, water in the livewells, two adults, and all their gear. Find the sweet spot for your hull heavy and it will run even better light setup light and it will fall on it's face loaded.

  6. Member
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    #6
    also FYI something i personally over looked... air temp plays a big roll in motor performance too. a couple degrees cooler or hotter can be a playing factor
    2004 Ranger Reata 180vs 8" rapid jack magnum CCM reeds 21P tempest plus- 2005 150 optimax 1B044209

  7. Member
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    #7
    Went to the dealer and my throttle was at 88%. It's at 100% now. Before I drove it I put it back to 3.5 PTP so I could compare apples to apples. it drove awesome like my old motor. I got 66.0 MPH @ 5650 RPM and had 24psi water pressure. I gained almost 5mph. Knowing i still need 200 more RPM, I pulled it out and raised it 1/4" and drove it again. I got 65.1@ 5360rpm and had 23psi. I lost speed and RPM. Should that happen? Should I raise it again by 1/4' and see what happens since I have plenty of water pressure? I didn't have time to change it and run it again today. Also the air temp was 95. When it gets colder will I gain the other 150-200 RPM? If I had 5800 RPM @ 3.5" I would be totally happy, it drove that well and my goal was 65 loaded and I got 66.

  8. Member
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    #8
    Something else must have happened to it because raising it might have slowed you down because of prop slip but it should have gained rpm's not lost 300. The throttle setting may have moved again. Air temps can change power on a motor but it takes more than a few degrees to make a difference but by November you'll be able to tell the difference and it should gain close to 200 rpm's.

  9. Member
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    #9
    I still don't believe the RPM on the Mercmonitor peak rpm screen because when I look at the prop slip calculator on Mercury's Web site, it says 1 for the first numbers and -3 for the second run. I noticed the peak RPMS at peak speed on the mercmonitor don't update immediately, you have to be there for a couple of seconds. I have it hooked to an old lowrance graph so i can watch water pressure in big numbers while i am driving. RPM is on that screen as well and I've seen higher RPM in real time than the mercmonitor shows in the peak speed and RPM screen. It's like it's sampling at some inerval. I'll know more with a little more time in the seat.

  10. Pat Goff
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    #10
    Raising your motor and losing rpms is not logical. I've never seen that happen. Not once.
    Pat Goff

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    Smithwick TX.

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  11. Banned
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    #11
    Quote Originally Posted by pmgoffjr View Post
    Raising your motor and losing rpms is not logical. I've never seen that happen. Not once.
    This^^^^ something isn't reading correctly

  12. Member
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    #12
    Slip would be 4% for the first run and 2% for the last but something is wrong it could be the Merc monitor is hooked up wrong. Can you hook the tach back up to it.

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    #13
    I should be able to get the old tach hooked back up today. I have been waiting on a female-female adapter cable to get the old gauges hooked back up and it came in yesterday. It's going to be a few days before I can test again though. It's weird that it dropped rpm at the same PTP when I was running at 88% throttle. I totally agree that something doesn't sound right. I think i have been as scientific as possible getting this data. Does anyone else see the lag in the peak RPM on the mercmonitor? The real time RPM doesnt lag, just the Peak. I am watching the real time RPM on the lowrance while simultaneously watching the peak on the mercmonitor. The data on the lowrance is coming fromthe mercmonitor. What prop slip calculator are you using to get your numbers or did I mess something up using the Mercury website calculator?

    Thanks everyone for your replies. It's nice to have a place to get a sanity check.

  14. Member
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    #14
    Mercury web site doesn't add one inch for a cupped SS prop. AA Prop Slip Calculator

  15. Member
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    #15
    I am finally out of the break-in period so I am playing with the prop to pad again. I know last time I posted my numbers it seemed not logical that as I raise my motor, I lose RPMs. Since it is cooler now than when I did it before, I thought I would try again. I have been raising it 1/16" at a time and here are my results:
    PTP RPM Speed
    3.5 5740 66.3
    3 7/16 5750 66
    3 3/8 5760 66.3
    3 5/16 5740 66.1

    I am not sure what is going on. Is it possible I lose lift at this point causing more boat to be in the water or something?

    Also, I have been playing with numbers on the prop slip calculator recommended by mdtritn. At 3 3/8" PTP I have 3% slip and 5760RPM which is in the correct operating range for this engine. Even if I got 5950 rpm with no more slip I would gain less than 2MPH. If I went down to a 22 pitch prop, and got 5950 RPM with 3% slip, I would lose speed and only have 65MPH.Am I not better off staying at a 23p prop with more MPH and less RPM, but still in the safe operating range at WOT? With all that said, I would like to try a 23 tempest and just see since it apparently like to be ran higher than my current fury.

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    #16
    Fury’s like to be ran deep . You have a light boat at1050 lbs . Fury is not going to run the best on that boat . A tempest 25 would be my choice or maybe a 24